How to print raw ESC/POS commands from ASP.NET directly to the client printer

Product WebClientPrint for ASP.NET Published 12/27/2013 Updated 07/03/2020 Author

Overview

Many kind of printers like dot-matrix, impact, kiosk, thermal, inkjet, etc; do internally handle ESC/POS (a.k.a. ESC/P) commands which are processed to produce the output printing. ESC/POS was designed by EPSON and is widely used by many other printer brands mainly on POS (Point Of Sales or Point of Services) scenarios like retail, banking, hospitality, and healthcare.

ESC/POS commands are very simple and the main character you'll find in each command is ESC i.e. ASCII hex 1B (or dec 27). Almost any ESC/POS command will start with the ESC (hex 1B) character although it's not the only one as you'll see in the next sample later. The main advantage of using raw ESC/POS commands for printing instead of using the built-in browser javascript printing (window.print();) is that the printing performance will be way faster; a factor that is key in the aforementioned scenarios. In ASP.NET websites, you'll be able to use raw printing feature thanks to our WebClientPrint for ASP.NET solution that was specially designed for this kind of printing needs.

In this walkthrough, you'll learn how to print raw ESC/POS commands from an ASP.NET website directly to the client printer without displaying a print dialog at all. You'll be able to print ESC/POS commands to the Default client printer as well as to any other installed printer at the client machine. This solution works with any popular browser like Chrome, Firefox, Opera & Safari on Windows, Linux, Raspberry Pi or Mac systems!

The ESC/POS commands that we'll use in this article will print out a simple retail receipt that will look like this:

A Sample Receipt printed from ASP.NET and created by using ESC/POS commands
A Sample Receipt printed from ASP.NET and created by using ESC/POS commands

How to specify ESC/POS commands in C# or VB

ESC/POS commands are composed of a set of simple bytes (from 00 up to FF in hex notation) and most of them always starts with ESC which is byte 1B.
Some commands require additional parameters which have to be expressed in bytes too. For example, the following shows how the ESC/POS command for "emphasized text " is found in the reference manual and how it should be specified in bytes.

  • ESC/POS command for: "Emphasized mode selected."
  • From the ESC/POS Reference Manual:
    ESC ! 8
  • It must be specified in bytes (HEX notation) as:
    0x1B!0x08 or &H1B!&H08
    Notice that ESC needs to be specified as 0x1B and the integer parameter value is NOT digit 8 char (hex 38) BUT byte hex 08!!! Be aware of the way you must specify commands & params values as a misunderstanding on this subject might carry unexpected printing results or no printing output at all.

Later on this article, you'll find the ESC/POS commands and their explanation that you can use in C# or VB to print the sample receipt shown above.

Try Online Demo!

Requirements

Development/Server-side

  WebClientPrint 6.0 for ASP.NET (or greater)
  ASP.NET 4.6.1+ or ASP.NET Core 2.0+
  Visual Studio 2015+
  jQuery 1.4.1+

Client-side

  WebClientPrint Processor 6.0 for Windows, Linux, Raspberry Pi & Mac

Follow up these steps

  • Open Visual Studio and create a new ASP.NET Website naming it PrintESCPOSSample
  • Add a NuGet reference to Neodynamic.SDK.WebClientPrint package to your project
  • Now follow up the instructions for each .NET Core, MVC/C#, MVC/VB, SPA/AngularJS+WebAPI, WebForms/CS or WebForms/VB:

    Creating/Editing Controllers

    Create a new Controller and name it WebClientPrintAPIController and then copy/paste the following code:

    
using Neodynamic.SDK.Web;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.AspNetCore.Authorization;

[Authorize]
public class WebClientPrintAPIController : Controller
{
	//IMPORTANT NOTE >>>>>>>>>>
	// We're going to use MemoryCache to store users related staff like
	// the list of printers and they have the WCPP client utility installed
	// BUT you can change it based on your dev needs!!!
	// For instance, you could use a Distributed Cache instead!
	//>>>>>>>>>>>>>>>>>>>>>>>>>
	private readonly IMemoryCache _MemoryCache;

	public WebClientPrintAPIController(IMemoryCache memCache)
	{
		_MemoryCache = memCache;
	}

	[AllowAnonymous]
	public IActionResult ProcessRequest()
	{
		//get session ID
		string sessionID = HttpContext.Request.Query["sid"].ToString();

		//get Query String
		string queryString = HttpContext.Request.QueryString.Value;

		try
		{
			//Determine and get the Type of Request 
			RequestType prType = WebClientPrint.GetProcessRequestType(queryString);

			if (prType == RequestType.GenPrintScript ||
				prType == RequestType.GenWcppDetectScript)
			{
				//Let WebClientPrint to generate the requested script
				byte[] script = WebClientPrint.GenerateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Request.Scheme), queryString);

				return File(script, "application/x-javascript", "WebClientPrintScript");
			}
			else if (prType == RequestType.ClientSetWcppVersion)
			{
				//This request is a ping from the WCPP utility
				//so store the session ID indicating it has the WCPP installed
				//also store the WCPP Version if available
				string wcppVersion = HttpContext.Request.Query["wcppVer"];
				if (string.IsNullOrEmpty(wcppVersion))
					wcppVersion = "1.0.0.0";

				_MemoryCache.Set(sessionID + "wcppInstalled", wcppVersion);
			}
			else if (prType == RequestType.ClientSetInstalledPrinters)
			{
				//WCPP Utility is sending the installed printers at client side
				//so store this info with the specified session ID
				string printers = HttpContext.Request.Query["printers"].ToString();
				if (!string.IsNullOrEmpty(printers) && printers.Length > 0)
					printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers));

				_MemoryCache.Set(sessionID + "printers", printers);

			}
			else if (prType == RequestType.ClientSetInstalledPrintersInfo)
			{
				//WCPP Utility is sending the client installed printers with detailed info
				//so store this info with the specified session ID
				//Printers Info is in JSON format
				string printersInfo = HttpContext.Request.Form["printersInfoContent"];

				if (string.IsNullOrEmpty(printersInfo) == false)
					printersInfo = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printersInfo));

				_MemoryCache.Set(sessionID + "printersInfo", printersInfo);


			}
			else if (prType == RequestType.ClientGetWcppVersion)
			{
				//return the WCPP version for the specified sid if any
				bool sidWcppVersion = (_MemoryCache.Get<string>(sessionID + "wcppInstalled") != null);

				return Ok(sidWcppVersion ? _MemoryCache.Get<string>(sessionID + "wcppInstalled") : "");

			}
			else if (prType == RequestType.ClientGetInstalledPrinters)
			{
				//return the installed printers for the specified sid if any
				bool sidHasPrinters = (_MemoryCache.Get<string>(sessionID + "printers") != null);

				return Ok(sidHasPrinters ? _MemoryCache.Get<string>(sessionID + "printers") : "");
			}
			else if (prType == RequestType.ClientGetInstalledPrintersInfo)
			{
				//return the installed printers with detailed info for the specified Session ID (sid) if any
				bool sidHasPrinters = (_MemoryCache.Get<string>(sessionID + "printersInfo") != null);

				return Ok(sidHasPrinters ? _MemoryCache.Get<string>(sessionID + "printersInfo") : "");
			}

		}
		catch
		{
			return BadRequest();
		}

		return Ok();
	}
}

    Edit the HomeController to the following code:

    
public class HomeController : Controller
{
    public IActionResult Index()
    {
        ViewData["WCPPDetectionScript"] = Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, Url.ActionContext.HttpContext.Request.Scheme), Url.ActionContext.HttpContext.Session.Id);

        return View();
    }

    public IActionResult PrintESCPOS()
    {
        return View();
    }

}

    Add a new Controller and name it PrintESCPOSController and paste the following code:

    
using Neodynamic.SDK.Web;

public class PrintESCPOSController : Controller
{
    private readonly IHostingEnvironment _hostEnvironment;

    public PrintESCPOSController(IHostingEnvironment hostEnvironment)
    {
        _hostEnvironment = hostEnvironment;
    }

    public IActionResult Index()
    {
        ViewData["WCPScript"] = Neodynamic.SDK.Web.WebClientPrint.CreateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, Url.ActionContext.HttpContext.Request.Scheme), Url.Action("PrintCommands", "PrintESCPOS", null, Url.ActionContext.HttpContext.Request.Scheme), Url.ActionContext.HttpContext.Session.Id);

        return View();
    }


	[Microsoft.AspNetCore.Authorization.AllowAnonymous]
    public IActionResult PrintCommands(string useDefaultPrinter, string printerName)
	{
		//Create ESC/POS commands for sample receipt
        string ESC = "0x1B"; //ESC byte in hex notation
        string NewLine = "0x0A"; //LF byte in hex notation

        string cmds = ESC + "@"; //Initializes the printer (ESC @)
        cmds += ESC + "!" + "0x38"; //Emphasized + Double-height + Double-width mode selected (ESC ! (8 + 16 + 32)) 56 dec => 38 hex
        cmds += "BEST DEAL STORES"; //text to print
        cmds += NewLine + NewLine;
        cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
        cmds += "COOKIES                   5.00"; 
        cmds += NewLine;
        cmds += "MILK 65 Fl oz             3.78";
        cmds += NewLine + NewLine;
        cmds += "SUBTOTAL                  8.78";
        cmds += NewLine;
        cmds += "TAX 5%                    0.44";
        cmds += NewLine;
        cmds += "TOTAL                     9.22";
        cmds += NewLine;
        cmds += "CASH TEND                10.00";
        cmds += NewLine;
        cmds += "CASH DUE                  0.78";
        cmds += NewLine + NewLine;
        cmds += ESC + "!" + "0x18"; //Emphasized + Double-height mode selected (ESC ! (16 + 8)) 24 dec => 18 hex
        cmds += "# ITEMS SOLD 2";
        cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
        cmds += NewLine + NewLine;
        cmds += "11/03/13  19:53:17";


		//Create a ClientPrintJob and send it back to the client!
		ClientPrintJob cpj = new ClientPrintJob();
		//set  ESCPOS commands to print...
		cpj.PrinterCommands = cmds;
		cpj.FormatHexValues = true;

		//set client printer...
		if (useDefaultPrinter == "checked" || printerName == "null")
			cpj.ClientPrinter = new DefaultPrinter();
		else
			cpj.ClientPrinter = new InstalledPrinter(printerName);
	

        return File(cpj.GetContent(), "application/octet-stream");
            
    }

}

    Creating/Editing Views

    The default View is for detecting whether the client machine has the WebClientPrint Processor (WCPP) Utility installed. Edit the Views / Shared / _Layout.cshtml file and add the folowing section to the BODY:

    Be sure this View links to jQuery 1.4.1+ file!

    
<body>
    ...
	
    @RenderSection("scripts", required: false)

	...
</body>

    Edit the Views / Home / Index.cshtml file and copy/paste the folowing code:

    
@{
    ViewBag.Title = "Home Page";
}


<div id="msgInProgress">
    <div id="mySpinner" style="width:32px;height:32px"></div>
    <br />
    <h3>Detecting WCPP utility at client side...</h3>
    <h3>Please wait a few seconds...</h3>
    <br />
</div>
<div id="msgInstallWCPP" style="display:none;">
    <h3>#1 Install WebClientPrint Processor (WCPP)!</h3>
    <p>
        <strong>WCPP is a native app (without any dependencies!)</strong> that handles all print jobs
        generated by the <strong>WebClientPrint for ASP.NET component</strong> at the server side. The WCPP
        is in charge of the whole printing process and can be
        installed on <strong>Windows, Linux, Mac & Raspberry Pi!</strong>
    </p>
    <p>
        <a href="//www.neodynamic.com/downloads/wcpp/" target="_blank" >Download and Install WCPP from Neodynamic website</a><br />
    </p>
    <h3>#2 After installing WCPP...</h3>
    <p>
        <a asp-controller="PrintESCPOS" asp-action="Index" >You can go and test the printing page...</a>
    </p>

</div>

@section scripts{
    
<script type="text/javascript">

    var wcppPingTimeout_ms = 60000; //60 sec
    var wcppPingTimeoutStep_ms = 500; //0.5 sec
                 
    function wcppDetectOnSuccess(){
        // WCPP utility is installed at the client side
        // redirect to WebClientPrint sample page
                
        // get WCPP version
        var wcppVer = arguments[0];
        if(wcppVer.substring(0, 1) == "6")
            window.location.href = '@Url.Action("Index", "PrintESCPOS")';
        else //force to install WCPP v6.0
            wcppDetectOnFailure();
    }

    function wcppDetectOnFailure() {
        // It seems WCPP is not installed at the client side
        // ask the user to install it
        $('#msgInProgress').hide();
        $('#msgInstallWCPP').show();
    }

</script>


@* WCPP detection script generated by HomeController *@

@Html.Raw(ViewData["WCPPDetectionScript"])


    }

    Add a new View with the following name and under such folders: Views / PrintESCPOS / Index.cshtml Then, copy/paste the folowing code:

    
<h3>Print ESCPOS commands</h3>

<div>
<label class="checkbox">
	<input type="checkbox" id="useDefaultPrinter" /> <strong>Print to Default printer</strong> or...
</label>
</div>

<div id="loadPrinters">
	Click to load and select one of the installed printers!
	<br />
	 <input type="button" onclick="javascript:jsWebClientPrint.getPrinters();" value="Load installed printers..." />
	<br /><br />
</div>

<div id="installedPrinters" style="visibility:hidden">
	<label for="installedPrinterName">Select an installed Printer:</label>
	<select name="installedPrinterName" id="installedPrinterName"></select>
</div>

<script type="text/javascript">
	var wcppGetPrintersTimeout_ms = 60000; //60 sec
    var wcppGetPrintersTimeoutStep_ms = 500; //0.5 sec

	function wcpGetPrintersOnSuccess() {
		// Display client installed printers
		if (arguments[0].length > 0) {
			var p = arguments[0].split("|");
			var options = '';
			for (var i = 0; i < p.length; i++) {
				options += '<option>' + p[i] + '</option>';
			}
			$('#installedPrinters').css('visibility', 'visible');
			$('#installedPrinterName').html(options);
			$('#installedPrinterName').focus();
			$('#loadPrinters').hide();
		} else {
			alert("No printers are installed in your system.");
		}
	}
	function wcpGetPrintersOnFailure() {
		// Do something if printers cannot be got from the client
		alert("No printers are installed in your system.");
	}
</script>

<br />

<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print('useDefaultPrinter=' + $('#useDefaultPrinter').attr('checked') + '&printerName=' + $('#installedPrinterName').val());" value="Print ESCPOS..." />


@section scripts{
    
@* Register the WebClientPrint script code generated by PrintESCPOSController. *@

@Html.Raw(ViewData["WCPScript"]);

    }

    Creating/Editing Controllers

    Create a new Controller and name it WebClientPrintAPIController and then copy/paste the following code:

    
public class WebClientPrintAPIController : Controller
{
 
    //*********************************
    // IMPORTANT NOTE 
    // In this sample we store users related stuff (like
    // the list of printers and whether they have the WCPP 
    // client utility installed) in the Application cache
    // object part of ASP.NET BUT you can change it to 
    // another different storage (like a DB or file server)!
    // which will be required in Load Balacing scenarios
    //*********************************
 
    [AllowAnonymous]
    public void ProcessRequest()
    {
        //get session ID
        string sessionID = (HttpContext.Request["sid"] != null ? HttpContext.Request["sid"] : null);
 
        //get Query String
        string queryString = HttpContext.Request.Url.Query;
 
        try
        {
            //Determine and get the Type of Request 
            RequestType prType = WebClientPrint.GetProcessRequestType(queryString);
 
            if (prType == RequestType.GenPrintScript ||
                prType == RequestType.GenWcppDetectScript)
            {
                //Let WebClientPrint to generate the requested script
                byte[] script = WebClientPrint.GenerateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Request.Url.Scheme), queryString);
 
                HttpContext.Response.ContentType = "text/javascript";
                HttpContext.Response.BinaryWrite(script);
                HttpContext.Response.End();
            }
            else if (prType == RequestType.ClientSetWcppVersion)
            {
                //This request is a ping from the WCPP utility
                //so store the session ID indicating it has the WCPP installed
                //also store the WCPP Version if available
                string wcppVersion = HttpContext.Request["wcppVer"];
                if (string.IsNullOrEmpty(wcppVersion))
                    wcppVersion = "1.0.0.0";
 
                HttpContext.Application.Set(sessionID + "wcppInstalled", wcppVersion);
            }
            else if (prType == RequestType.ClientSetInstalledPrinters)
            {
                //WCPP Utility is sending the installed printers at client side
                //so store this info with the specified session ID
                string printers = HttpContext.Request["printers"];
                if (string.IsNullOrEmpty(printers) == false)
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers));
 
                HttpContext.Application.Set(sessionID + "printers", printers);
 
            }
            else if (prType == RequestType.ClientSetInstalledPrintersInfo)
            {
                //WCPP Utility is sending the client installed printers with detailed info
                //so store this info with the specified session ID
                //Printers Info is in JSON format
                string printersInfo = HttpContext.Request.Form["printersInfoContent"];
 
                if (string.IsNullOrEmpty(printersInfo) == false)
                    printersInfo = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printersInfo));
 
                HttpContext.Application.Set(sessionID + "printersInfo", printersInfo);
 
 
            }
            else if (prType == RequestType.ClientGetWcppVersion)
            {
                //return the WCPP version for the specified sid if any
                bool sidWcppVersion = (HttpContext.Application.Get(sessionID + "wcppInstalled") != null);
 
                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write((sidWcppVersion ? HttpContext.Application.Get(sessionID + "wcppInstalled") : ""));
                HttpContext.Response.End();
 
            }
            else if (prType == RequestType.ClientGetInstalledPrinters)
            {
                //return the installed printers for the specified sid if any
                bool sidHasPrinters = (HttpContext.Application.Get(sessionID + "printers") != null);
 
                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write((sidHasPrinters ? HttpContext.Application.Get(sessionID + "printers") : ""));
                HttpContext.Response.End();
            }
            else if (prType == RequestType.ClientGetInstalledPrintersInfo)
            {
                //return the installed printers with detailed info for the specified Session ID (sid) if any
                bool sidHasPrinters = (HttpContext.Application[sessionID + "printersInfo"] != null);
 
                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write(sidHasPrinters ? HttpContext.Application[sessionID + "printersInfo"] : "");
 
            }
 
        }
        catch (Exception ex)
        {
            HttpContext.Response.StatusCode = 500;
            HttpContext.Response.ContentType = "text/plain";
            HttpContext.Response.Write(ex.Message + " - StackTrace: " + ex.StackTrace);
            HttpContext.Response.End();
        }
 
             
    }
}

    Edit the HomeController to the following code:

    
public class HomeController : Controller
{
    public ActionResult Index()
    {

        ViewBag.WCPPDetectionScript = Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Request.Url.Scheme), HttpContext.Session.SessionID);

        return View();
    }

    public ActionResult PrintESCPOS()
    {
        return View();
    }

}

    Add a new Controller and name it PrintESCPOSController and paste the following code:

    
using Neodynamic.SDK.Web;

public class PrintESCPOSController : Controller
{
	public ActionResult Index()
	{
		ViewBag.WCPScript = WebClientPrint.CreateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Request.Url.Scheme), Url.Action("PrintCommands", "PrintESCPOS", null, HttpContext.Request.Url.Scheme), HttpContext.Session.SessionID);

		return View();
	}

	[AllowAnonymous]
	public void PrintCommands(string useDefaultPrinter, string printerName)
	{
		 //Create ESC/POS commands for sample receipt
        string ESC = "0x1B"; //ESC byte in hex notation
        string NewLine = "0x0A"; //LF byte in hex notation

        string cmds = ESC + "@"; //Initializes the printer (ESC @)
        cmds += ESC + "!" + "0x38"; //Emphasized + Double-height + Double-width mode selected (ESC ! (8 + 16 + 32)) 56 dec => 38 hex
        cmds += "BEST DEAL STORES"; //text to print
        cmds += NewLine + NewLine;
        cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
        cmds += "COOKIES                   5.00"; 
        cmds += NewLine;
        cmds += "MILK 65 Fl oz             3.78";
        cmds += NewLine + NewLine;
        cmds += "SUBTOTAL                  8.78";
        cmds += NewLine;
        cmds += "TAX 5%                    0.44";
        cmds += NewLine;
        cmds += "TOTAL                     9.22";
        cmds += NewLine;
        cmds += "CASH TEND                10.00";
        cmds += NewLine;
        cmds += "CASH DUE                  0.78";
        cmds += NewLine + NewLine;
        cmds += ESC + "!" + "0x18"; //Emphasized + Double-height mode selected (ESC ! (16 + 8)) 24 dec => 18 hex
        cmds += "# ITEMS SOLD 2";
        cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
        cmds += NewLine + NewLine;
        cmds += "11/03/13  19:53:17";


		//Create a ClientPrintJob and send it back to the client!
		ClientPrintJob cpj = new ClientPrintJob();
		//set  ESCPOS commands to print...
		cpj.PrinterCommands = cmds;
		cpj.FormatHexValues = true;

		//set client printer...
		if (useDefaultPrinter == "checked" || printerName == "null")
			cpj.ClientPrinter = new DefaultPrinter();
		else
			cpj.ClientPrinter = new InstalledPrinter(printerName);
		
		//send it...
		System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream";
		System.Web.HttpContext.Current.Response.BinaryWrite(cpj.GetContent());
		System.Web.HttpContext.Current.Response.End();
		
	}

}

    Creating/Editing Views

    The default View is for detecting whether the client machine has the WebClientPrint Processor (WCPP) Utility installed. Edit the Views / Shared / _Layout.cshtml file and add the folowing section to the BODY:

    Be sure this View links to jQuery 1.4.1+ file!

    
<body>
    ...
	
    @RenderSection("scripts", required: false)

	...
</body>

    Edit the Views / Home / Index.cshtml file and copy/paste the folowing code:

    
@{
    ViewBag.Title = "Home Page";
}


<div id="msgInProgress">
    <div id="mySpinner" style="width:32px;height:32px"></div>
    <br />
    <h3>Detecting WCPP utility at client side...</h3>
    <h3>Please wait a few seconds...</h3>
    <br />
</div>
<div id="msgInstallWCPP" style="display:none;">
    <h3>#1 Install WebClientPrint Processor (WCPP)!</h3>
    <p>
        <strong>WCPP is a native app (without any dependencies!)</strong> that handles all print jobs
        generated by the <strong>WebClientPrint for ASP.NET component</strong> at the server side. The WCPP
        is in charge of the whole printing process and can be
        installed on <strong>Windows, Linux, Mac & Raspberry Pi!</strong>
    </p>
    <p>
        <a href="//www.neodynamic.com/downloads/wcpp/" target="_blank" >Download and Install WCPP from Neodynamic website</a><br />
    </p>
    <h3>#2 After installing WCPP...</h3>
    <p>
        <a href="@Url.Action("Index", "PrintESCPOS")" >You can go and test the printing page...</a>
    </p>

</div>

@section scripts{
    
<script type="text/javascript">

    var wcppPingTimeout_ms = 60000; //60 sec
    var wcppPingTimeoutStep_ms = 500; //0.5 sec
                     
    function wcppDetectOnSuccess(){
        // WCPP utility is installed at the client side
        // redirect to WebClientPrint sample page
                
        // get WCPP version
        var wcppVer = arguments[0];
        if(wcppVer.substring(0, 1) == "6")
            window.location.href = '@Url.Action("Index", "PrintESCPOS")';
        else //force to install WCPP v6.0
            wcppDetectOnFailure();
    }

    function wcppDetectOnFailure() {
        // It seems WCPP is not installed at the client side
        // ask the user to install it
        $('#msgInProgress').hide();
        $('#msgInstallWCPP').show();
    }

</script>


@* WCPP detection script generated by HomeController *@

@Html.Raw(ViewBag.WCPPDetectionScript)


    }

    Add a new View with the following name and under such folders: Views / PrintESCPOS / Index.cshtml Then, copy/paste the folowing code:

    
<h3>Print ESCPOS commands</h3>

<div>
<label class="checkbox">
	<input type="checkbox" id="useDefaultPrinter" /> <strong>Print to Default printer</strong> or...
</label>
</div>

<div id="loadPrinters">
	Click to load and select one of the installed printers!
	<br />
	 <input type="button" onclick="javascript:jsWebClientPrint.getPrinters();" value="Load installed printers..." />
	<br /><br />
</div>

<div id="installedPrinters" style="visibility:hidden">
	<label for="installedPrinterName">Select an installed Printer:</label>
	<select name="installedPrinterName" id="installedPrinterName"></select>
</div>

<script type="text/javascript">
	var wcppGetPrintersTimeout_ms = 60000; //60 sec
    var wcppGetPrintersTimeoutStep_ms = 500; //0.5 sec

	function wcpGetPrintersOnSuccess() {
		// Display client installed printers
		if (arguments[0].length > 0) {
			var p = arguments[0].split("|");
			var options = '';
			for (var i = 0; i < p.length; i++) {
				options += '<option>' + p[i] + '</option>';
			}
			$('#installedPrinters').css('visibility', 'visible');
			$('#installedPrinterName').html(options);
			$('#installedPrinterName').focus();
			$('#loadPrinters').hide();
		} else {
			alert("No printers are installed in your system.");
		}
	}
	function wcpGetPrintersOnFailure() {
		// Do something if printers cannot be got from the client
		alert("No printers are installed in your system.");
	}
</script>

<br />

<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print('useDefaultPrinter=' + $('#useDefaultPrinter').attr('checked') + '&printerName=' + $('#installedPrinterName').val());" value="Print ESCPOS..." />


@section scripts{
    
@* Register the WebClientPrint script code generated by PrintESCPOSController. *@

@Html.Raw(ViewBag.WCPScript);

    }

    Creating/Editing Controllers

    Create a new Controller and name it WebClientPrintAPIController and then copy/paste the following code:

    
Imports Neodynamic.SDK.Web
 
Namespace Controllers
    Public Class WebClientPrintAPIController
        Inherits Controller
 
        ' GET: WebClientPrintAPI
        Function Index() As ActionResult
            Return View()
        End Function
 
        '*********************************
        ' IMPORTANT NOTE 
        ' In this sample we store users related stuff (like
        ' the list of printers and whether they have the WCPP 
        ' client utility installed) in the Application cache
        ' object part of ASP.NET BUT you can change it to 
        ' another different storage (like a DB or file server)!
        ' which will be required in Load Balacing scenarios
        '*********************************
 
        <AllowAnonymous>
        Public Sub ProcessRequest()
            'get session ID
            Dim sessionID As String = (If(HttpContext.Request("sid") IsNot Nothing, HttpContext.Request("sid"), Nothing))
 
            'get Query String
            Dim queryString As String = HttpContext.Request.Url.Query
 
            Try
                'Determine and get the Type of Request 
                Dim prType As RequestType = WebClientPrint.GetProcessRequestType(queryString)
 
                If prType = RequestType.GenPrintScript OrElse prType = RequestType.GenWcppDetectScript Then
                    'Let WebClientPrint to generate the requested script
                    Dim script As Byte() = WebClientPrint.GenerateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", Nothing, HttpContext.Request.Url.Scheme), queryString)
 
                    HttpContext.Response.ContentType = "text/javascript"
                    HttpContext.Response.BinaryWrite(script)
                    HttpContext.Response.End()
 
                ElseIf prType = RequestType.ClientSetWcppVersion Then
                    'This request is a ping from the WCPP utility
                    'so store the session ID indicating it has the WCPP installed
                    'also store the WCPP Version if available
                    Dim wcppVersion As String = HttpContext.Request("wcppVer")
                    If String.IsNullOrEmpty(wcppVersion) Then
                        wcppVersion = "1.0.0.0"
                    End If
 
                    HttpContext.Application.Set(sessionID & "wcppInstalled", wcppVersion)
 
                ElseIf prType = RequestType.ClientSetInstalledPrinters Then
                    'WCPP Utility is sending the installed printers at client side
                    'so store this info with the specified session ID
                    Dim printers As String = HttpContext.Request("printers")
                    If String.IsNullOrEmpty(printers) = False Then
                        printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers))
                    End If
 
 
                    HttpContext.Application.Set(sessionID & "printers", printers)
 
                ElseIf prType = RequestType.ClientSetInstalledPrintersInfo Then
                    'WCPP Utility is sending the installed printers at client side
                    'so store this info with the specified session ID
                    'Printers Info is in JSON format
                    Dim printersInfo As String = HttpContext.Request.Form("printersInfoContent")
                    If Not String.IsNullOrEmpty(printersInfo) Then
                        printersInfo = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printersInfo))
                    End If
 
                    HttpContext.Application.Set(sessionID & "printersInfo", printersInfo)
 
 
                ElseIf prType = RequestType.ClientGetWcppVersion Then
                    'return the WCPP version for the specified sid if any
                    Dim sidWcppVersion As Boolean = (HttpContext.Application(sessionID & "wcppInstalled") IsNot Nothing)
 
                    HttpContext.Response.ContentType = "text/plain"
                    If (sidWcppVersion) Then
                        HttpContext.Response.Write(HttpContext.Application(sessionID & "wcppInstalled").ToString())
                    End If
                    HttpContext.Response.End()
 
                ElseIf prType = RequestType.ClientGetInstalledPrinters Then
                    'return the installed printers for the specified sid if any
                    Dim sidHasPrinters As Boolean = (HttpContext.Application(sessionID & "printers") IsNot Nothing)
 
                    HttpContext.Response.ContentType = "text/plain"
                    If (sidHasPrinters) Then
                        HttpContext.Response.Write(HttpContext.Application(sessionID & "printers").ToString())
                    End If
                    HttpContext.Response.End()
 
                ElseIf prType = RequestType.ClientGetInstalledPrintersInfo Then
                    'return the installed printers with detailed info for the specified Session ID (sid) if any
                    Dim sidHasPrinters As Boolean = (HttpContext.Application(sessionID & "printersInfo") IsNot Nothing)
 
                    HttpContext.Response.ContentType = "text/plain"
 
                    If (sidHasPrinters) Then
                        HttpContext.Response.Write(HttpContext.Application(sessionID & "printersInfo").ToString())
                    End If
                    HttpContext.Response.End()
                End If
            Catch ex As Exception
                HttpContext.Response.StatusCode = 500
                HttpContext.Response.ContentType = "text/plain"
                HttpContext.Response.Write(ex.Message + " - StackTrace: " + ex.StackTrace)
                HttpContext.Response.End()
            End Try
 
 
        End Sub
 
    End Class
End Namespace

    Edit the HomeController to the following code:

    
Public Class HomeController
    Inherits System.Web.Mvc.Controller

    Function Index() As ActionResult
        ViewData("WCPPDetectionScript") = Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript(Url.Action("ProcessRequest", "WebClientPrintAPI", Nothing, HttpContext.Request.Url.Scheme), HttpContext.Session.SessionID)

        Return View()
    End Function

    Function PrintESCPOS() As ActionResult

        Return View()
    End Function

End Class

    Add a new Controller and name it PrintESCPOSController and paste the following code:

    
Imports Neodynamic.SDK.Web

Namespace Controllers
    Public Class PrintESCPOSController
        Inherits Controller

        Function Index() As ActionResult

            ViewData("WCPScript") = Neodynamic.SDK.Web.WebClientPrint.CreateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", Nothing, HttpContext.Request.Url.Scheme), Url.Action("PrintCommands", "PrintESCPOS", Nothing, HttpContext.Request.Url.Scheme), HttpContext.Session.SessionID)

            Return View()
        End Function

        <AllowAnonymous> Public Sub PrintCommands(useDefaultPrinter As String, printerName As String)

            'Create ESC/POS commands for sample receipt
            Dim ESC As String = "0x1B" 'ESC byte in hex notation
            Dim NewLine As String = "0x0A" 'LF byte in hex notation

            Dim cmds As String = ESC + "@" 'Initializes the printer (ESC @)
            cmds += ESC + "!" + "0x38" 'Emphasized + Double-height + Double-width mode selected (ESC ! (8 + 16 + 32)) 56 dec => 38 hex
            cmds += "BEST DEAL STORES" 'text to print
            cmds += NewLine + NewLine
            cmds += ESC + "!" + "0x00" 'Character font A selected (ESC ! 0)
            cmds += "COOKIES                   5.00" 
            cmds += NewLine
            cmds += "MILK 65 Fl oz             3.78"
            cmds += NewLine + NewLine
            cmds += "SUBTOTAL                  8.78"
            cmds += NewLine
            cmds += "TAX 5%                    0.44"
            cmds += NewLine
            cmds += "TOTAL                     9.22"
            cmds += NewLine
            cmds += "CASH TEND                10.00"
            cmds += NewLine
            cmds += "CASH DUE                  0.78"
            cmds += NewLine + NewLine
            cmds += ESC + "!" + "0x18" 'Emphasized + Double-height mode selected (ESC ! (16 + 8)) 24 dec => 18 hex
            cmds += "# ITEMS SOLD 2"
            cmds += ESC + "!" + "0x00" 'Character font A selected (ESC ! 0)
            cmds += NewLine + NewLine
            cmds += "11/03/13  19:53:17"

		    'Create a ClientPrintJob and send it back to the client!
		    Dim cpj As New ClientPrintJob()
		    'set  ESCPOS commands to print...
		    cpj.PrinterCommands = cmds
		    cpj.FormatHexValues = True    

            If (useDefaultPrinter = "checked" OrElse printerName = "null") Then
                cpj.ClientPrinter = New DefaultPrinter()
            Else
                cpj.ClientPrinter = New InstalledPrinter(System.Web.HttpUtility.UrlDecode(printerName))
            End If

            System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream"
            System.Web.HttpContext.Current.Response.BinaryWrite(cpj.GetContent())
            System.Web.HttpContext.Current.Response.End()

        End Sub
    End Class
End Namespace

    Creating/Editing Views

    The default View is for detecting whether the client machine has the WebClientPrint Processor (WCPP) Utility installed. Edit the Views / Shared / _Layout.vbhtml file and add the folowing section to the BODY:

    Be sure this View links to jQuery 1.4.1+ file!

    
<body>
    ...
	
    @RenderSection("scripts", required: False)

	...
</body>

    Edit the Views / Home / Index.vbhtml file and copy/paste the folowing code:

    
@Code
    ViewData("Title") = "Home Page"
End Code


<div id="msgInProgress">
    <div id="mySpinner" style="width:32px;height:32px"></div>
    <br />
    <h3>Detecting WCPP utility at client side...</h3>
    <h3>Please wait a few seconds...</h3>
    <br />
</div>
<div id="msgInstallWCPP" style="display:none;">
    <h3>#1 Install WebClientPrint Processor (WCPP)!</h3>
    <p>
        <strong>WCPP is a native app (without any dependencies!)</strong> that handles all print jobs
        generated by the <strong>WebClientPrint for ASP.NET component</strong> at the server side. The WCPP
        is in charge of the whole printing process and can be
        installed on <strong>Windows, Linux, Mac & Raspberry Pi!</strong>
    </p>
    <p>
        <a href="//www.neodynamic.com/downloads/wcpp/" target="_blank" >Download and Install WCPP from Neodynamic website</a><br />
    </p>
    <h3>#2 After installing WCPP...</h3>
    <p>
        <a href="@Url.Action("Index", "PrintESCPOS")" >You can go and test the printing page...</a>
    </p>

</div>

@section scripts
    
<script type="text/javascript">

    var wcppPingTimeout_ms = 60000; //60 sec
    var wcppPingTimeoutStep_ms = 500; //0.5 sec
                     
    function wcppDetectOnSuccess(){
        // WCPP utility is installed at the client side
        // redirect to WebClientPrint sample page
                
        // get WCPP version
        var wcppVer = arguments[0];
        if(wcppVer.substring(0, 1) == "6")
            window.location.href = '@Url.Action("Index", "PrintESCPOS")';
        else //force to install WCPP v6.0
            wcppDetectOnFailure();
    }

    function wcppDetectOnFailure() {
        // It seems WCPP is not installed at the client side
        // ask the user to install it
        $('#msgInProgress').hide();
        $('#msgInstallWCPP').show();
    }

</script>


@* WCPP detection script generated by HomeController *@

@Html.Raw(ViewData("WCPPDetectionScript"))


    }

End Section

    Add a new View with the following name and under such folders: Views / PrintESCPOS / Index.vbhtml Then, copy/paste the folowing code:

    
<h3>Print ESCPOS commands</h3>

<div>
<label class="checkbox">
	<input type="checkbox" id="useDefaultPrinter" /> <strong>Print to Default printer</strong> or...
</label>
</div>

<div id="loadPrinters">
	Click to load and select one of the installed printers!
	<br />
	 <input type="button" onclick="javascript:jsWebClientPrint.getPrinters();" value="Load installed printers..." />
	<br /><br />
</div>

<div id="installedPrinters" style="visibility:hidden">
	<label for="installedPrinterName">Select an installed Printer:</label>
	<select name="installedPrinterName" id="installedPrinterName"></select>
</div>

<script type="text/javascript">
	var wcppGetPrintersTimeout_ms = 60000; //60 sec
    var wcppGetPrintersTimeoutStep_ms = 500; //0.5 sec

    function wcpGetPrintersOnSuccess() {
		// Display client installed printers
		if (arguments[0].length > 0) {
			var p = arguments[0].split("|");
			var options = '';
			for (var i = 0; i < p.length; i++) {
				options += '<option>' + p[i] + '</option>';
			}
			$('#installedPrinters').css('visibility', 'visible');
			$('#installedPrinterName').html(options);
			$('#installedPrinterName').focus();
			$('#loadPrinters').hide();
		} else {
			alert("No printers are installed in your system.");
		}
	}
	function wcpGetPrintersOnFailure() {
		// Do something if printers cannot be got from the client
		alert("No printers are installed in your system.");
	}
</script>

<br />

<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print('useDefaultPrinter=' + $('#useDefaultPrinter').attr('checked') + '&printerName=' + $('#installedPrinterName').val());" value="Print ESCPOS..." />


@section scripts
    
    @* Register the WebClientPrint script code generated by PrintESCPOSController. *@

    @Html.Raw(ViewData("WCPScript"))

@end section

    Creating/Editing Controllers

    Create a new Controller and name it WebClientPrintAPIController and then copy/paste the following code:

    
public class WebClientPrintAPIController : Controller
{
 
    //*********************************
    // IMPORTANT NOTE 
    // In this sample we store users related stuff (like
    // the list of printers and whether they have the WCPP 
    // client utility installed) in the Application cache
    // object part of ASP.NET BUT you can change it to 
    // another different storage (like a DB or file server)!
    // which will be required in Load Balacing scenarios
    //*********************************
    [AllowAnonymous]
    public void ProcessRequest()
    {
        //get session ID
        string sessionID = (HttpContext.Request["sid"] != null ? HttpContext.Request["sid"] : null);
 
        //get Query String
        string queryString = HttpContext.Request.Url.Query;
 
        try
        {
            //Determine and get the Type of Request 
            RequestType prType = WebClientPrint.GetProcessRequestType(queryString);
 
            if (prType == RequestType.GenPrintScript ||
                prType == RequestType.GenWcppDetectScript)
            {
                //Let WebClientPrint to generate the requested script
                byte[] script = WebClientPrint.GenerateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Request.Url.Scheme), queryString);
 
                HttpContext.Response.ContentType = "text/javascript";
                HttpContext.Response.BinaryWrite(script);
                HttpContext.Response.End();
            }
            else if (prType == RequestType.ClientSetWcppVersion)
            {
                //This request is a ping from the WCPP utility
                //so store the session ID indicating it has the WCPP installed
                //also store the WCPP Version if available
                string wcppVersion = HttpContext.Request["wcppVer"];
                if (string.IsNullOrEmpty(wcppVersion))
                    wcppVersion = "1.0.0.0";
 
                HttpContext.Application.Set(sessionID + "wcppInstalled", wcppVersion);
            }
            else if (prType == RequestType.ClientSetInstalledPrinters)
            {
                //WCPP Utility is sending the installed printers at client side
                //so store this info with the specified session ID
                string printers = HttpContext.Request["printers"];
                if (string.IsNullOrEmpty(printers) == false)
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers));
 
                HttpContext.Application.Set(sessionID + "printers", printers);
 
            }
            else if (prType == RequestType.ClientSetInstalledPrintersInfo)
            {
                //WCPP Utility is sending the client installed printers with detailed info
                //so store this info with the specified session ID
                //Printers Info is in JSON format
                string printersInfo = HttpContext.Request.Form["printersInfoContent"];
 
                if (string.IsNullOrEmpty(printersInfo) == false)
                    printersInfo = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printersInfo));
 
                HttpContext.Application.Set(sessionID + "printersInfo", printersInfo);
 
 
            }
            else if (prType == RequestType.ClientGetWcppVersion)
            {
                //return the WCPP version for the specified sid if any
                bool sidWcppVersion = (HttpContext.Application.Get(sessionID + "wcppInstalled") != null);
 
                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write((sidWcppVersion ? HttpContext.Application.Get(sessionID + "wcppInstalled") : ""));
                HttpContext.Response.End();
 
            }
            else if (prType == RequestType.ClientGetInstalledPrinters)
            {
                //return the installed printers for the specified sid if any
                bool sidHasPrinters = (HttpContext.Application.Get(sessionID + "printers") != null);
 
                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write((sidHasPrinters ? HttpContext.Application.Get(sessionID + "printers") : ""));
                HttpContext.Response.End();
            }
            else if (prType == RequestType.ClientGetInstalledPrintersInfo)
            {
                //return the installed printers with detailed info for the specified Session ID (sid) if any
                bool sidHasPrinters = (HttpContext.Application[sessionID + "printersInfo"] != null);
 
                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write(sidHasPrinters ? HttpContext.Application[sessionID + "printersInfo"] : "");
 
            }
 
        }
        catch (Exception ex)
        {
            HttpContext.Response.StatusCode = 500;
            HttpContext.Response.ContentType = "text/plain";
            HttpContext.Response.Write(ex.Message + " - StackTrace: " + ex.StackTrace);
            HttpContext.Response.End();
        }
 
             
    }
     
}

    Add a new Controller and name it PrintESCPOSController and paste the following code:

    
using Neodynamic.SDK.Web;

public class PrintESCPOSController : Controller
{
	public ActionResult Index()
	{
		return View();
	}

	[AllowAnonymous]
	public void PrintCommands(string useDefaultPrinter, string printerName)
	{
		 //Create ESC/POS commands for sample receipt
        string ESC = "0x1B"; //ESC byte in hex notation
        string NewLine = "0x0A"; //LF byte in hex notation

        string cmds = ESC + "@"; //Initializes the printer (ESC @)
        cmds += ESC + "!" + "0x38"; //Emphasized + Double-height + Double-width mode selected (ESC ! (8 + 16 + 32)) 56 dec => 38 hex
        cmds += "BEST DEAL STORES"; //text to print
        cmds += NewLine + NewLine;
        cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
        cmds += "COOKIES                   5.00"; 
        cmds += NewLine;
        cmds += "MILK 65 Fl oz             3.78";
        cmds += NewLine + NewLine;
        cmds += "SUBTOTAL                  8.78";
        cmds += NewLine;
        cmds += "TAX 5%                    0.44";
        cmds += NewLine;
        cmds += "TOTAL                     9.22";
        cmds += NewLine;
        cmds += "CASH TEND                10.00";
        cmds += NewLine;
        cmds += "CASH DUE                  0.78";
        cmds += NewLine + NewLine;
        cmds += ESC + "!" + "0x18"; //Emphasized + Double-height mode selected (ESC ! (16 + 8)) 24 dec => 18 hex
        cmds += "# ITEMS SOLD 2";
        cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
        cmds += NewLine + NewLine;
        cmds += "11/03/13  19:53:17";


		//Create a ClientPrintJob and send it back to the client!
		ClientPrintJob cpj = new ClientPrintJob();
		//set  ESCPOS commands to print...
		cpj.PrinterCommands = cmds;
		cpj.FormatHexValues = true;

		//set client printer...
		if (useDefaultPrinter == "checked" || printerName == "null")
			cpj.ClientPrinter = new DefaultPrinter();
		else
			cpj.ClientPrinter = new InstalledPrinter(printerName);
		
		//send it...
		System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream";
		System.Web.HttpContext.Current.Response.BinaryWrite(cpj.GetContent());
		System.Web.HttpContext.Current.Response.End();
		
	}

}

    Creating SPA by using AngularJS

    Create a new index.html file that will act as our view for detecting whether the client machine has the WebClientPrint Processor (WCPP) Utility installed as well as for listing client printers and to finally perform client side printing. This SPA features two parts or sections, one for "Detecting WCPP" and the other one for "Client side printing". The ClientPrintJob is generated by the controller created above from the Web API server side code. Copy/Paste the following markup:

    Be sure this html file links to jQuery 1.4.1+ and to AngularJS 1.6.4+ files!

    
<!DOCTYPE html>
<html>
<head>
    <title></title>
	<meta charset="utf-8" />
    <script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
</head>
<body>

    <div ng-app="myApp" ng-controller="myCtrl">

        <div id="wcppDetection">
            <div id="msgInProgress">
                <div id="mySpinner" style="width:32px;height:32px"></div>
                <br />
                <h3>Detecting WCPP utility at client side...</h3>
                <h3>Please wait a few seconds...</h3>
                <br />
            </div>
            <div id="msgInstallWCPP" style="display:none;">
                <h3>#1 Install WebClientPrint Processor (WCPP)!</h3>
                <p>
                    <strong>WCPP is a native app (without any dependencies!)</strong> that handles all print jobs
                    generated by the <strong>WebClientPrint for ASP.NET component</strong> at the server side. The WCPP
                    is in charge of the whole printing process and can be
                    installed on <strong>Windows, Linux, Mac & Raspberry Pi!</strong>
                </p>
                <p>
                    <a href="//www.neodynamic.com/downloads/wcpp/" target="_blank">Download and Install WCPP from Neodynamic website</a><br />
                </p>
                <h3>#2 After installing WCPP...</h3>
                <p>
                    <a href="#" onclick="javascript:$('#wcppDetection').hide();$('#printSection').show();">You can go and test the printing page...</a>
                </p>

                <script type="text/javascript">

                    var wcppPingTimeout_ms = 60000; //60 sec
                    var wcppPingTimeoutStep_ms = 500; //0.5 sec

                    function wcppDetectOnSuccess() {
                        // WCPP utility is installed at the client side
                        // redirect to WebClientPrint sample page

                        // get WCPP version
                        var wcppVer = arguments[0];
                        if (wcppVer.substring(0, 1) == "6"){
                            $('#wcppDetection').hide();
                            $('#printSection').show();
                        }   
                        else //force to install WCPP v6.0
                            wcppDetectOnFailure();
                    }

                    function wcppDetectOnFailure() {
                        // It seems WCPP is not installed at the client side
                        // ask the user to install it
                        $('#msgInProgress').hide();
                        $('#msgInstallWCPP').show();
                    }

                </script>

            </div>
            
            <input type="hidden" id="sid" name="sid" ng-value="sid" />
            <script>
                $(function () {
                    //Gen script for WCPP detection
                    $.getScript('/WebClientPrintAPI/ProcessRequest?d=' + $('#sid').val());
                });
            </script>

        </div>

        <div id="printSection" style="display:none;">
            <h3>Print ESCPOS commands</h3>

            <div>
                <label class="checkbox">
                    <input type="checkbox" id="useDefaultPrinter" /> <strong>Print to Default printer</strong> or...
                </label>
            </div>

            <div id="loadPrinters">
                Click to load and select one of the installed printers!
                <br />
                <input type="button" onclick="javascript:jsWebClientPrint.getPrinters();" value="Load installed printers..." />
                <br /><br />
            </div>

            <div id="installedPrinters" style="visibility:hidden">
                <label for="installedPrinterName">Select an installed Printer:</label>
                <select name="installedPrinterName" id="installedPrinterName"></select>
            </div>

            <script type="text/javascript">
	            var wcppGetPrintersTimeout_ms = 60000; //60 sec
                var wcppGetPrintersTimeoutStep_ms = 500; //0.5 sec

	            function wcpGetPrintersOnSuccess() {
		            // Display client installed printers
		            if (arguments[0].length > 0) {
			            var p = arguments[0].split("|");
			            var options = '';
			            for (var i = 0; i < p.length; i++) {
				            options += '<option>' + p[i] + '</option>';
			            }
			            $('#installedPrinters').css('visibility', 'visible');
			            $('#installedPrinterName').html(options);
			            $('#installedPrinterName').focus();
			            $('#loadPrinters').hide();
		            } else {
			            alert("No printers are installed in your system.");
		            }
	            }
	            function wcpGetPrintersOnFailure() {
		            // Do something if printers cannot be got from the client
		            alert("No printers are installed in your system.");
	            }
            </script>

            <br />

            <input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print('useDefaultPrinter=' + $('#useDefaultPrinter').attr('checked') + '&printerName=' + $('#installedPrinterName').val());" value="Print ESCPOS..." />

            <script>
                $(function () {
                    // Create Base64 Object
                    var Base64 = { _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=", encode: function (e) { var t = ""; var n, r, i, s, o, u, a; var f = 0; e = Base64._utf8_encode(e); while (f < e.length) { n = e.charCodeAt(f++); r = e.charCodeAt(f++); i = e.charCodeAt(f++); s = n >> 2; o = (n & 3) << 4 | r >> 4; u = (r & 15) << 2 | i >> 6; a = i & 63; if (isNaN(r)) { u = a = 64 } else if (isNaN(i)) { a = 64 } t = t + this._keyStr.charAt(s) + this._keyStr.charAt(o) + this._keyStr.charAt(u) + this._keyStr.charAt(a) } return t }, _utf8_encode: function (e) { e = e.replace(/\r\n/g, "\n"); var t = ""; for (var n = 0; n < e.length; n++) { var r = e.charCodeAt(n); if (r < 128) { t += String.fromCharCode(r) } else if (r > 127 && r < 2048) { t += String.fromCharCode(r >> 6 | 192); t += String.fromCharCode(r & 63 | 128) } else { t += String.fromCharCode(r >> 12 | 224); t += String.fromCharCode(r >> 6 & 63 | 128); t += String.fromCharCode(r & 63 | 128) } } return t } }

                    // Creat script for client side printing
                    var rootUrl = $(location).attr('protocol') + "//" + $(location).attr('host');
                    var ABSOLUTE_URL_TO_PRINT_JOB_CONTROLLER = rootUrl + '/PrintESCPOS/PrintCommands';
                    $.getScript('/WebClientPrintAPI/ProcessRequest?v6.0.0.0&' + new Date().getTime() + '&sid=' + $('#sid').val() + '&u=' + Base64.encode(ABSOLUTE_URL_TO_PRINT_JOB_CONTROLLER));
                    
                });
            </script>


        </div>
    </div>

    <script>
        var app = angular.module('myApp', []);
        app.controller('myCtrl', function($scope) {
            $scope.sid = new Date().getTime();
        });
    </script>
</body>
</html>

    Creating HTTP Handlers

    Create a new Generic Handler and name it WebClientPrintAPI and then copy/paste the following code:

    
public class WebClientPrintAPI : IHttpHandler {
 
    //*********************************
    // IMPORTANT NOTE 
    // In this sample we store users related stuff (like
    // the list of printers and whether they have the WCPP 
    // client utility installed) in the Application cache
    // object part of ASP.NET BUT you can change it to 
    // another different storage (like a DB or file server)!
    // which will be required in Load Balacing scenarios
    //*********************************
 
    public void ProcessRequest (HttpContext context) {
        //get session ID
        string sessionID = (context.Request["sid"] != null) ? context.Request["sid"].ToString() : null;
 
        //get Query String
        string queryString = context.Request.Url.Query;
 
        try
        {
            //Determine and get the Type of Request 
            RequestType prType = WebClientPrint.GetProcessRequestType(queryString);
 
            if (prType == RequestType.GenPrintScript ||
                prType == RequestType.GenWcppDetectScript)
            {
                //Let WebClientPrint to generate the requested script
                byte[] script = WebClientPrint.GenerateScript(context.Request.Url.AbsoluteUri.Replace(queryString, ""), queryString);
 
                context.Response.ContentType = "text/javascript";
                context.Response.BinaryWrite(script);
            }
            else if (prType == RequestType.ClientSetWcppVersion)
            {
                //This request is a ping from the WCPP utility
                //so store the session ID indicating this user has the WCPP installed
                //also store the WCPP Version if available
                string wcppVersion = context.Request["wcppVer"];
                if (string.IsNullOrEmpty(wcppVersion))
                    wcppVersion = "1.0.0.0";
 
                context.Application.Set(sessionID + "wcppInstalled", wcppVersion);
            }
            else if (prType == RequestType.ClientSetInstalledPrinters)
            {
                //WCPP Utility is sending the installed printers at client side
                //so store this info with the specified session ID
                string printers = context.Request["printers"];
                if (string.IsNullOrEmpty(printers) == false)
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers));
 
                context.Application.Set(sessionID + "printers", printers);
 
            }
            else if (prType == RequestType.ClientSetInstalledPrintersInfo)
            {
                //WCPP Utility is sending the client installed printers with detailed info
                //so store this info with the specified session ID
                //Printers Info is in JSON format
                string printersInfo = context.Request.Form["printersInfoContent"];
 
                if (string.IsNullOrEmpty(printersInfo) == false)
                    printersInfo = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printersInfo));
 
                context.Application.Set(sessionID + "printersInfo", printersInfo);
 
            }
            else if (prType == RequestType.ClientGetWcppVersion)
            {
                //return the WCPP version for the specified Session ID (sid) if any
                bool sidWcppVersion = (context.Application[sessionID + "wcppInstalled"] != null);
 
                context.Response.ContentType = "text/plain";
                context.Response.Write(sidWcppVersion ? context.Application[sessionID + "wcppInstalled"] : "");
 
            }
            else if (prType == RequestType.ClientGetInstalledPrinters)
            {
                //return the installed printers for the specified Session ID (sid) if any
                bool sidHasPrinters = (context.Application[sessionID + "printers"] != null);
 
                context.Response.ContentType = "text/plain";
                context.Response.Write(sidHasPrinters ? context.Application[sessionID + "printers"] : "");
 
            }
            else if (prType == RequestType.ClientGetInstalledPrintersInfo)
            {
                //return the installed printers with detailed info for the specified Session ID (sid) if any
                bool sidHasPrinters = (context.Application[sessionID + "printersInfo"] != null);
 
                context.Response.ContentType = "text/plain";
                context.Response.Write(sidHasPrinters ? context.Application[sessionID + "printersInfo"] : "");
 
            }
 
        }
        catch (Exception ex)
        {
            context.Response.StatusCode = 500;
            context.Response.ContentType = "text/plain";
            context.Response.Write(ex.Message + " - " + ex.StackTrace);
        }
 
 
 
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }
 
}

    Create a new Generic Handler and name it PrintESCPOSHandler and then copy/paste the following code:

    
<%@ WebHandler Language="C#" Class="PrintESCPOSHandler" %>

using System;
using System.Web;

using Neodynamic.SDK.Web;

public class PrintESCPOSHandler : IHttpHandler {
    
    /*############### IMPORTANT!!! ############
    If your website requires AUTHENTICATION, then you MUST configure THIS Handler file
    to be ANONYMOUS access allowed!!!
      ######################################### */

    public void ProcessRequest (HttpContext context) {

        if (WebClientPrint.ProcessPrintJob(context.Request.Url.Query))
        {
            bool useDefaultPrinter = (context.Request["useDefaultPrinter"] == "checked");
            string printerName = context.Server.UrlDecode(context.Request["printerName"]);

             //Create ESC/POS commands for sample receipt
            string ESC = "0x1B"; //ESC byte in hex notation
            string NewLine = "0x0A"; //LF byte in hex notation

            string cmds = ESC + "@"; //Initializes the printer (ESC @)
            cmds += ESC + "!" + "0x38"; //Emphasized + Double-height + Double-width mode selected (ESC ! (8 + 16 + 32)) 56 dec => 38 hex
            cmds += "BEST DEAL STORES"; //text to print
            cmds += NewLine + NewLine;
            cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
            cmds += "COOKIES                   5.00"; 
            cmds += NewLine;
            cmds += "MILK 65 Fl oz             3.78";
            cmds += NewLine + NewLine;
            cmds += "SUBTOTAL                  8.78";
            cmds += NewLine;
            cmds += "TAX 5%                    0.44";
            cmds += NewLine;
            cmds += "TOTAL                     9.22";
            cmds += NewLine;
            cmds += "CASH TEND                10.00";
            cmds += NewLine;
            cmds += "CASH DUE                  0.78";
            cmds += NewLine + NewLine;
            cmds += ESC + "!" + "0x18"; //Emphasized + Double-height mode selected (ESC ! (16 + 8)) 24 dec => 18 hex
            cmds += "# ITEMS SOLD 2";
            cmds += ESC + "!" + "0x00"; //Character font A selected (ESC ! 0)
            cmds += NewLine + NewLine;
            cmds += "11/03/13  19:53:17";


		    //Create a ClientPrintJob and send it back to the client!
		    ClientPrintJob cpj = new ClientPrintJob();
		    //set  ESCPOS commands to print...
		    cpj.PrinterCommands = cmds;
		    cpj.FormatHexValues = true;

		    //set client printer...
		    if (useDefaultPrinter || printerName == "null")
			    cpj.ClientPrinter = new DefaultPrinter();
		    else
			    cpj.ClientPrinter = new InstalledPrinter(printerName);
		
		    //send it...		    
            context.Response.ContentType = "application/octet-stream";
            context.Response.BinaryWrite(cpj.GetContent());
            context.Response.End();
            
        }
        
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}

    Creating/Editing WebForm Pages

    Be sure ALL *.aspx link to jQuery 1.4.1+ file!

    The default page is for detecting whether the client machine has the WebClientPrint Processor (WCPP) Utility installed. Edit the Default.aspx file and copy/paste the following code inside the BODY:

    

<div id="msgInProgress">
    <div id="mySpinner" style="width:32px;height:32px"></div>
    <br />
    <h3>Detecting WCPP utility at client side...</h3>
    <h3>Please wait a few seconds...</h3>
    <br />
</div>
<div id="msgInstallWCPP" style="display:none;">
    <h3>#1 Install WebClientPrint Processor (WCPP)!</h3>
    <p>
        <strong>WCPP is a native app (without any dependencies!)</strong> that handles all print jobs
        generated by the <strong>WebClientPrint for ASP.NET component</strong> at the server side. The WCPP
        is in charge of the whole printing process and can be
        installed on <strong>Windows, Linux, Mac & Raspberry Pi!</strong>
    </p>
    <p>
        <a href="//www.neodynamic.com/downloads/wcpp/" target="_blank" >Download and Install WCPP from Neodynamic website</a><br />
    </p>
    <h3>#2 After installing WCPP...</h3>
    <p>
        <a href="PrintESCPOS.aspx" >You can go and test the printing page...</a>
    </p>

</div>

    
<script type="text/javascript">

    var wcppPingTimeout_ms = 60000; //60 sec
    var wcppPingTimeoutStep_ms = 500; //0.5 sec
                     
    function wcppDetectOnSuccess(){
        // WCPP utility is installed at the client side
        // redirect to WebClientPrint sample page
                
        // get WCPP version
        var wcppVer = arguments[0];
        if(wcppVer.substring(0, 1) == "6")
            window.location.href = 'PrintESCPOS.aspx';
        else //force to install WCPP v6.0
            wcppDetectOnFailure();
    }

    function wcppDetectOnFailure() {
        // It seems WCPP is not installed at the client side
        // ask the user to install it
        $('#msgInProgress').hide();
        $('#msgInstallWCPP').show();
    }

</script>


<%-- WCPP detection script code --%>

<%=Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript(HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/WebClientPrintAPI.ashx", HttpContext.Current.Session.SessionID)%>

    Add a new page and name it PrintESCPOS.aspx. Copy/paste the following code inside the BODY:

    
<h3>Print ESCPOS commands</h3>

<div>
<label class="checkbox">
	<input type="checkbox" id="useDefaultPrinter" /> <strong>Print to Default printer</strong> or...
</label>
</div>

<div id="loadPrinters">
	Click to load and select one of the installed printers!
	<br />
	 <input type="button" onclick="javascript:jsWebClientPrint.getPrinters();" value="Load installed printers..." />
	<br /><br />
</div>

<div id="installedPrinters" style="visibility:hidden">
	<label for="installedPrinterName">Select an installed Printer:</label>
	<select name="installedPrinterName" id="installedPrinterName"></select>
</div>

<script type="text/javascript">
	var wcppGetPrintersTimeout_ms = 60000; //60 sec
    var wcppGetPrintersTimeoutStep_ms = 500; //0.5 sec

	function wcpGetPrintersOnSuccess() {
		// Display client installed printers
		if (arguments[0].length > 0) {
			var p = arguments[0].split("|");
			var options = '';
			for (var i = 0; i < p.length; i++) {
				options += '<option>' + p[i] + '</option>';
			}
			$('#installedPrinters').css('visibility', 'visible');
			$('#installedPrinterName').html(options);
			$('#installedPrinterName').focus();
			$('#loadPrinters').hide();
		} else {
			alert("No printers are installed in your system.");
		}
	}
	function wcpGetPrintersOnFailure() {
		// Do something if printers cannot be got from the client
		alert("No printers are installed in your system.");
	}
</script>

<br />

<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print('useDefaultPrinter=' + $('#useDefaultPrinter').attr('checked') + '&printerName=' + $('#installedPrinterName').val());" value="Print ESCPOS..." />

<%-- Register the WebClientPrint script code --%>

<%=Neodynamic.SDK.Web.WebClientPrint.CreateScript(HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/WebClientPrintAPI.ashx", HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/PrintESCPOSHandler.ashx", HttpContext.Current.Session.SessionID)%>

    Creating HTTP Handlers

    Create a new Generic Handler and name it WebClientPrintAPI and then copy/paste the following code:

    
<%@ WebHandler Language="VB" Class="WebClientPrintAPI" %>
 
Imports System
Imports System.Web
 
Imports Neodynamic.SDK.Web
 
 
Public Class WebClientPrintAPI : Implements IHttpHandler
 
    '*********************************
    ' IMPORTANT NOTE 
    ' In this sample we store users related stuff (like
    ' the list of printers and whether they have the WCPP 
    ' client utility installed) in the Application cache
    ' object part of ASP.NET BUT you can change it to 
    ' another different storage (like a DB or file server)!
    ' which will be required in Load Balacing scenarios
    '*********************************
 
    Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
        'get session ID
        Dim sessionID As String = ""
        If (context.Request("sid") IsNot Nothing) Then
            sessionID = context.Request("sid")
        End If
 
        'get Query String
        Dim queryString As String = context.Request.Url.Query
 
        Try
            'Determine and get the Type of Request 
            Dim prType As RequestType = WebClientPrint.GetProcessRequestType(queryString)
 
            If prType = RequestType.GenPrintScript OrElse prType = RequestType.GenWcppDetectScript Then
                'Let WebClientPrint to generate the requested script
                Dim script As Byte() = WebClientPrint.GenerateScript(context.Request.Url.AbsoluteUri.Replace(queryString, ""), queryString)
 
                context.Response.ContentType = "text/javascript"
                context.Response.BinaryWrite(script)
            ElseIf prType = RequestType.ClientSetWcppVersion Then
                'This request is a ping from the WCPP utility
                'so store the session ID indicating this user has the WCPP installed
                'also store the WCPP Version if available
                Dim wcppVersion As String = context.Request("wcppVer")
                If String.IsNullOrEmpty(wcppVersion) Then
                    wcppVersion = "1.0.0.0"
                End If
 
                context.Application.Set(sessionID & "wcppInstalled", wcppVersion)
            ElseIf prType = RequestType.ClientSetInstalledPrinters Then
                'WCPP Utility is sending the installed printers at client side
                'so store this info with the specified session ID
                Dim printers As String = context.Request("printers")
                If Not String.IsNullOrEmpty(printers) Then
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers))
                End If
 
                context.Application.Set(sessionID & "printers", printers)
 
            ElseIf prType = RequestType.ClientSetInstalledPrintersInfo Then
                'WCPP Utility is sending the installed printers at client side
                'so store this info with the specified session ID
                'Printers Info is in JSON format
                Dim printersInfo As String = context.Request.Form("printersInfoContent")
                If Not String.IsNullOrEmpty(printersInfo) Then
                    printersInfo = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printersInfo))
                End If
 
                context.Application.Set(sessionID & "printersInfo", printersInfo)
 
            ElseIf prType = RequestType.ClientGetWcppVersion Then
                'return the WCPP version for the specified Session ID (sid) if any
                Dim sidWcppVersion As Boolean = (context.Application(sessionID & "wcppInstalled") IsNot Nothing)
 
                context.Response.ContentType = "text/plain"
                If (sidWcppVersion) Then
                    context.Response.Write(context.Application(sessionID & "wcppInstalled").ToString())
                End If
 
            ElseIf prType = RequestType.ClientGetInstalledPrinters Then
                'return the installed printers for the specified Session ID (sid) if any
                Dim sidHasPrinters As Boolean = (context.Application(sessionID & "printers") IsNot Nothing)
 
                context.Response.ContentType = "text/plain"
 
                If (sidHasPrinters) Then
                    context.Response.Write(context.Application(sessionID & "printers").ToString())
                End If
 
            ElseIf prType = RequestType.ClientGetInstalledPrintersInfo Then
                'return the installed printers with detailed info for the specified Session ID (sid) if any
                Dim sidHasPrinters As Boolean = (context.Application(sessionID & "printersInfo") IsNot Nothing)
 
                context.Response.ContentType = "text/plain"
 
                If (sidHasPrinters) Then
                    context.Response.Write(context.Application(sessionID & "printersInfo").ToString())
                End If
            End If
        Catch ex As Exception
            context.Response.StatusCode = 500
            context.Response.ContentType = "text/plain"
            context.Response.Write(ex.Message + " - " + ex.StackTrace)
        End Try
 
 
 
    End Sub
 
 
    Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
        Get
            Return False
        End Get
    End Property
 
End Class

    Create a new Generic Handler and name it PrintESCPOSHandler and then copy/paste the following code:

    
<%@ WebHandler Language="VB" Class="PrintESCPOSHandler" %>

Imports System
Imports System.Web

Imports Neodynamic.SDK.Web

Public Class PrintESCPOSHandler : Implements IHttpHandler


    '############### IMPORTANT!!! ############
    ' If your website requires AUTHENTICATION, then you MUST configure THIS Handler file
    ' to be ANONYMOUS access allowed!!!
    '######################################### 


    Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest

        If WebClientPrint.ProcessPrintJob(context.Request.Url.Query) Then
            Dim useDefaultPrinter As Boolean = (context.Request("useDefaultPrinter") = "checked")
            Dim printerName As String = context.Server.UrlDecode(context.Request("printerName"))

            'Create ESC/POS commands for sample receipt
            Dim ESC As String = "0x1B" 'ESC byte in hex notation
            Dim NewLine As String = "0x0A" 'LF byte in hex notation

            Dim cmds As String = ESC + "@" 'Initializes the printer (ESC @)
            cmds += ESC + "!" + "0x38" 'Emphasized + Double-height + Double-width mode selected (ESC ! (8 + 16 + 32)) 56 dec => 38 hex
            cmds += "BEST DEAL STORES" 'text to print
            cmds += NewLine + NewLine
            cmds += ESC + "!" + "0x00" 'Character font A selected (ESC ! 0)
            cmds += "COOKIES                   5.00" 
            cmds += NewLine
            cmds += "MILK 65 Fl oz             3.78"
            cmds += NewLine + NewLine
            cmds += "SUBTOTAL                  8.78"
            cmds += NewLine
            cmds += "TAX 5%                    0.44"
            cmds += NewLine
            cmds += "TOTAL                     9.22"
            cmds += NewLine
            cmds += "CASH TEND                10.00"
            cmds += NewLine
            cmds += "CASH DUE                  0.78"
            cmds += NewLine + NewLine
            cmds += ESC + "!" + "0x18" 'Emphasized + Double-height mode selected (ESC ! (16 + 8)) 24 dec => 18 hex
            cmds += "# ITEMS SOLD 2"
            cmds += ESC + "!" + "0x00" 'Character font A selected (ESC ! 0)
            cmds += NewLine + NewLine
            cmds += "11/03/13  19:53:17"

		    'Create a ClientPrintJob and send it back to the client!
		    Dim cpj As New ClientPrintJob()
		    'set  ESCPOS commands to print...
		    cpj.PrinterCommands = cmds
		    cpj.FormatHexValues = True

            Dim cpj As New ClientPrintJob()
            cpj.PrintFile = file
            If useDefaultPrinter OrElse printerName = "null" Then
                cpj.ClientPrinter = New DefaultPrinter()
            Else
                cpj.ClientPrinter = New InstalledPrinter(printerName)
            End If

            context.Response.ContentType = "application/octet-stream"
            context.Response.BinaryWrite(cpj.GetContent())
            context.Response.End()
            
        End If

    End Sub


    Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
        Get
            Return False
        End Get
    End Property

End Class

    Creating/Editing WebForm Pages

    Be sure ALL *.aspx link to jQuery 1.4.1+ file!

    The default page is for detecting whether the client machine has the WebClientPrint Processor (WCPP) Utility installed. Edit the Default.aspx file and copy/paste the following code inside the BODY:

    

<div id="msgInProgress">
    <div id="mySpinner" style="width:32px;height:32px"></div>
    <br />
    <h3>Detecting WCPP utility at client side...</h3>
    <h3>Please wait a few seconds...</h3>
    <br />
</div>
<div id="msgInstallWCPP" style="display:none;">
    <h3>#1 Install WebClientPrint Processor (WCPP)!</h3>
    <p>
        <strong>WCPP is a native app (without any dependencies!)</strong> that handles all print jobs
        generated by the <strong>WebClientPrint for ASP.NET component</strong> at the server side. The WCPP
        is in charge of the whole printing process and can be
        installed on <strong>Windows, Linux, Mac & Raspberry Pi!</strong>
    </p>
    <p>
        <a href="//www.neodynamic.com/downloads/wcpp/" target="_blank" >Download and Install WCPP from Neodynamic website</a><br />
    </p>
    <h3>#2 After installing WCPP...</h3>
    <p>
        <a href="PrintESCPOS.aspx" >You can go and test the printing page...</a>
    </p>

</div>

    
<script type="text/javascript">

    var wcppPingTimeout_ms = 60000; //60 sec
    var wcppPingTimeoutStep_ms = 500; //0.5 sec
                     
    function wcppDetectOnSuccess(){
        // WCPP utility is installed at the client side
        // redirect to WebClientPrint sample page
                
        // get WCPP version
        var wcppVer = arguments[0];
        if(wcppVer.substring(0, 1) == "6")
            window.location.href = 'PrintESCPOS.aspx';
        else //force to install WCPP v6.0
            wcppDetectOnFailure();
    }

    function wcppDetectOnFailure() {
        // It seems WCPP is not installed at the client side
        // ask the user to install it
        $('#msgInProgress').hide();
        $('#msgInstallWCPP').show();
    }

</script>


<%-- WCPP detection script code --%>

<%=Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript(HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/WebClientPrintAPI.ashx", HttpContext.Current.Session.SessionID)%>

    Add a new page and name it PrintESCPOS.aspx. Copy/paste the following code inside the BODY:

    
<h3>Print ESCPOS commands</h3>

<div>
<label class="checkbox">
	<input type="checkbox" id="useDefaultPrinter" /> <strong>Print to Default printer</strong> or...
</label>
</div>

<div id="loadPrinters">
	Click to load and select one of the installed printers!
	<br />
	 <input type="button" onclick="javascript:jsWebClientPrint.getPrinters();" value="Load installed printers..." />
	<br /><br />
</div>

<div id="installedPrinters" style="visibility:hidden">
	<label for="installedPrinterName">Select an installed Printer:</label>
	<select name="installedPrinterName" id="installedPrinterName"></select>
</div>

<script type="text/javascript">
	var wcppGetPrintersTimeout_ms = 60000; //60 sec
    var wcppGetPrintersTimeoutStep_ms = 500; //0.5 sec

	function wcpGetPrintersOnSuccess() {
		// Display client installed printers
		if (arguments[0].length > 0) {
			var p = arguments[0].split("|");
			var options = '';
			for (var i = 0; i < p.length; i++) {
				options += '<option>' + p[i] + '</option>';
			}
			$('#installedPrinters').css('visibility', 'visible');
			$('#installedPrinterName').html(options);
			$('#installedPrinterName').focus();
			$('#loadPrinters').hide();
		} else {
			alert("No printers are installed in your system.");
		}
	}
	function wcpGetPrintersOnFailure() {
		// Do something if printers cannot be got from the client
		alert("No printers are installed in your system.");
	}
</script>

<br />

<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print('useDefaultPrinter=' + $('#useDefaultPrinter').attr('checked') + '&printerName=' + $('#installedPrinterName').val());" value="Print ESCPOS..." />

<%-- Register the WebClientPrint script code --%>

<%=Neodynamic.SDK.Web.WebClientPrint.CreateScript(HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/WebClientPrintAPI.ashx", HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/PrintESCPOSHandler.ashx", HttpContext.Current.Session.SessionID)%>
  • That's it! Run your website and test it. Click on Print ESCPOS to print the ESCPOS Commands without print dialog. You can print it to the Default client printer or you can get a list of the installed printers available at the client machine.

    NOTE You can also print directly to any LPT Parallel Port, RS232 Serial Port or IP/Ethernet Printer although these scenarios have not been considered in this article for simplicity. For further details on those scenarios, please contact our tech support.

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