How to print multiple files to client printers from ASP.NET

Product WebClientPrint for ASP.NET Published 07/19/2013 Updated 07/03/2020 Author Neodynamic

Overview

Suppose you have an ASP.NET website and you need to print two different documents or reports to two different printers installed at the client machine. Let's say you want to print an "Invoice" to Printer1 and a "Dispatch Form" to Printer2. Both Printer1 & Printer2 are available at the client machine.

The new PrintFileGroup feature of WebClientPrint for ASP.NET will allow you to get that working by just writing a few lines of code. The great thing about this is that you can print those files without displaying any print dialog to the user i.e. a silently printing approach!

In this walkthrough, you'll learn how to print multiple files or documents (like MS Word *.doc or *.docx; MS Excel *.xls or *.xlsx; Adobe PDF; Text files or images) from an ASP.NET website to different printers installed at the client machine without displaying any print dialog. Best of, this solution works with any browser on Windows OS like IE (6 or later), Chrome, Firefox, Opera & Safari as well as on Linux, Raspberry Pi & Mac OS clients!

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 PrintFilesSample
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 PrintFiles()
    {
        return View();
    }

}

Here we'll construct the code that allows many files to be printed to different printers at the client side. To get a file to be printed to a specified printer, you must specify a file name with the following format:

fileName + "_PRINT_TO_" + printerName + fileExtension

So, if we have an Invoice.doc file that we want to print to Printer1 on the client machine, then the file name must be formatted to this Invoice_PRINT_TO_Printer1.doc

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


using Neodynamic.SDK.Web;

public class PrintFilesController : Controller
{
    private readonly IHostingEnvironment _hostEnvironment;

    public PrintFilesController(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("PrintMyFiles", "PrintFiles", null, Url.ActionContext.HttpContext.Request.Scheme), Url.ActionContext.HttpContext.Session.Id);

        return View();
    }


	[Microsoft.AspNetCore.Authorization.AllowAnonymous]
    public IActionResult PrintMyFiles()
	{
		
		//Create a ClientPrintJob 
        ClientPrintJob cpj = new ClientPrintJob();
        //set client printer, for multiple files use DefaultPrinter...
        cpj.ClientPrinter = new DefaultPrinter();
        //set files-printers group by using special formatting!!!
        //Invoice.doc PRINT TO Printer1
        cpj.PrintFileGroup.Add(new PrintFile(_hostEnvironment.ContentRootPath + "/files/Invoice.doc", "Invoice_PRINT_TO_Printer1.doc"));
        //DispatchForm.xls PRINT TO Printer2
        cpj.PrintFileGroup.Add(new PrintFile(_hostEnvironment.ContentRootPath + "/files/DispatchForm.xls", "DispatchForm_PRINT_TO_Printer2.xls"));

        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="PrintFiles" 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", "PrintFiles")';
        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 / PrintFiles / Index.cshtml Then, copy/paste the folowing code:


<h1>How to print multiple files to client printers from ASP.NET</h1>
    Please change the source code to match your printer names and files to test it locally
    <br /><br />
    <input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print();" value="Print Files..." />


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

@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 PrintFiles()
    {
        return View();
    }

}

fileName + "_PRINT_TO_" + printerName + fileExtension

So, if we have an Invoice.doc file that we want to print to Printer1 on the client machine, then the file name must be formatted to this Invoice_PRINT_TO_Printer1.doc

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


using Neodynamic.SDK.Web;

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

		return View();
	}

	[AllowAnonymous]
	public void PrintMyFiles()
	{
		
		//Create a ClientPrintJob 
        ClientPrintJob cpj = new ClientPrintJob();
        //set client printer, for multiple files use DefaultPrinter...
        cpj.ClientPrinter = new DefaultPrinter();
        //set files-printers group by using special formatting!!!
        //Invoice.doc PRINT TO Printer1
        cpj.PrintFileGroup.Add(new PrintFile(System.Web.HttpContext.Server.MapPath("~/files/Invoice.doc"), "Invoice_PRINT_TO_Printer1.doc"));
        //DispatchForm.xls PRINT TO Printer2
        cpj.PrintFileGroup.Add(new PrintFile(System.Web.HttpContext.Server.MapPath("~/files/DispatchForm.xls"), "DispatchForm_PRINT_TO_Printer2.xls"));

	    //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

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", "PrintFiles")" >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", "PrintFiles")';
        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 / PrintFiles / index.cshtml Then, copy/paste the folowing code:


<h1>How to print multiple files to client printers from ASP.NET</h1>
    Please change the source code to match your printer names and files to test it locally
    <br /><br />
    <input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print();" value="Print Files..." />


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

@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 PrintFiles() As ActionResult

        Return View()
    End Function

End Class

fileName + "_PRINT_TO_" + printerName + fileExtension

So, if we have an Invoice.doc file that we want to print to Printer1 on the client machine, then the file name must be formatted to this Invoice_PRINT_TO_Printer1.doc

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


Imports Neodynamic.SDK.Web

Namespace Controllers
    Public Class PrintFilesController
        Inherits Controller

        Function Index() As ActionResult

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

            Return View()
        End Function

        <AllowAnonymous> Public Sub PrintMyFiles()

            'Create a ClientPrintJob 
            Dim cpj As New ClientPrintJob()
            'set client printer, for multiple files use DefaultPrinter...
            cpj.ClientPrinter = New DefaultPrinter()
            'set files-printers group by using special formatting!!!
            'Invoice.doc PRINT TO Printer1
            cpj.PrintFileGroup.Add(New PrintFile(System.Web.HttpContext.Server.MapPath("~/files/Invoice.doc"), "Invoice_PRINT_TO_Printer1.doc"))
            'DispatchForm.xls PRINT TO Printer2
            cpj.PrintFileGroup.Add(New PrintFile(System.Web.HttpContext.Server.MapPath("~/files/DispatchForm.xls"), "DispatchForm_PRINT_TO_Printer2.xls"))   

            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", "PrintFiles")" >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", "PrintFiles")';
        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 / PrintFiles / index.vbhtml Then, copy/paste the folowing code:


<h1>How to print multiple files to client printers from ASP.NET</h1>
Please change the source code to match your printer names and files to test it locally
<br /><br />
<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print();" value="Print Files..." />

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

    @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();
        }
 
             
    }
     
}

fileName + "_PRINT_TO_" + printerName + fileExtension

So, if we have an Invoice.doc file that we want to print to Printer1 on the client machine, then the file name must be formatted to this Invoice_PRINT_TO_Printer1.doc

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


using Neodynamic.SDK.Web;

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

	[AllowAnonymous]
	public void PrintMyFiles(string useDefaultPrinter, string printerName)
	{
		//Create a ClientPrintJob 
        ClientPrintJob cpj = new ClientPrintJob();
        //set client printer, for multiple files use DefaultPrinter...
        cpj.ClientPrinter = new DefaultPrinter();
        //set files-printers group by using special formatting!!!
        //Invoice.doc PRINT TO Printer1
        cpj.PrintFileGroup.Add(new PrintFile(System.Web.HttpContext.Server.MapPath("~/files/Invoice.doc"), "Invoice_PRINT_TO_Printer1.doc"));
        //DispatchForm.xls PRINT TO Printer2
        cpj.PrintFileGroup.Add(new PrintFile(System.Web.HttpContext.Server.MapPath("~/files/DispatchForm.xls"), "DispatchForm_PRINT_TO_Printer2.xls"));

		//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;">
            <h1>How to print multiple files to client printers from ASP.NET</h1>
            Please change the source code to match your printer names and files to test it locally
            <br /><br />
            <input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print();" value="Print Files..." />


            <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 + '/PrintFiles/PrintMyFiles';
                    $.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;
        }
    }
 
}

fileName + "_PRINT_TO_" + printerName + fileExtension

So, if we have an Invoice.doc file that we want to print to Printer1 on the client machine, then the file name must be formatted to this Invoice_PRINT_TO_Printer1.doc

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


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

using System;
using System.Web;

using Neodynamic.SDK.Web;

public class PrintPDFHandler : 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))
        {
            
		    //Create a ClientPrintJob 
            ClientPrintJob cpj = new ClientPrintJob();
            //set client printer, for multiple files use DefaultPrinter...
            cpj.ClientPrinter = new DefaultPrinter();
            //set files-printers group by using special formatting!!!
            //Invoice.doc PRINT TO Printer1
            cpj.PrintFileGroup.Add(new PrintFile(context.Server.MapPath("~/files/Invoice.doc"), "Invoice_PRINT_TO_Printer1.doc"));
            //DispatchForm.xls PRINT TO Printer2
            cpj.PrintFileGroup.Add(new PrintFile(context.Server.MapPath("~/files/DispatchForm.xls"), "DispatchForm_PRINT_TO_Printer2.xls"));

		    //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="PrintFiles.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 = 'PrintFiles.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 PrintFiles.aspx. Copy/paste the following code inside the BODY:


<h1>How to print multiple files to client printers from ASP.NET</h1>
Please change the source code to match your printer names and files to test it locally
<br /><br />
<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print();" value="Print Files..." />

<%-- 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 + "/PrintFilesHandler.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

fileName + "_PRINT_TO_" + printerName + fileExtension

So, if we have an Invoice.doc file that we want to print to Printer1 on the client machine, then the file name must be formatted to this Invoice_PRINT_TO_Printer1.doc

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


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

Imports System
Imports System.Web

Imports Neodynamic.SDK.Web

Public Class PrintPDFHandler : 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
            
            'Create a ClientPrintJob 
            Dim cpj As New ClientPrintJob()
            'set client printer, for multiple files use DefaultPrinter...
            cpj.ClientPrinter = New DefaultPrinter()
            'set files-printers group by using special formatting!!!
            'Invoice.doc PRINT TO Printer1
            cpj.PrintFileGroup.Add(New PrintFile(context.Server.MapPath("~/files/Invoice.doc"), "Invoice_PRINT_TO_Printer1.doc"))
            'DispatchForm.xls PRINT TO Printer2
            cpj.PrintFileGroup.Add(New PrintFile(context.Server.MapPath("~/files/DispatchForm.xls"), "DispatchForm_PRINT_TO_Printer2.xls"))    

            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!



<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="PrintFiles.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 = 'PrintFiles.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 PrintFiles.aspx. Copy/paste the following code inside the BODY:


<h1>How to print multiple files to client printers from ASP.NET</h1>
Please change the source code to match your printer names and files to test it locally
<br /><br />
<input type="button" style="font-size:18px" onclick="javascript:jsWebClientPrint.print();" value="Print Files..." />

<%-- 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 + "/PrintFilesHandler.ashx", HttpContext.Current.Session.SessionID)%>

That's it! Run your website and test it.

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How to print multiple files to client printers from ASP.NET

Overview

Requirements

Development/Server-side

Client-side

Follow up these steps

Creating/Editing Controllers

Creating/Editing Views

Be sure this View links to jQuery 1.4.1+ file!

Creating/Editing Controllers

Creating/Editing Views

Be sure this View links to jQuery 1.4.1+ file!

Creating/Editing Controllers

Creating/Editing Views

Be sure this View links to jQuery 1.4.1+ file!

Creating/Editing Controllers

Creating SPA by using AngularJS

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

Creating HTTP Handlers

Creating/Editing WebForm Pages

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

Creating HTTP Handlers

Creating/Editing WebForm Pages

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

Useful? Share it!

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Download Printer Emulator SDKs

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Download Virtual Printer Drivers

Virtual ZPL Printer Driver Convert, Print, Preview & Render ZPL

Download On-Premise Web APIs for Docker

Barcode Professional Encoder / Writer / Generator

ThermalLabel Design & Print Barcode Thermal Labels

ZPL Printer Emulator SDK Convert, Preview & Render ZPL to Image & PDF

JS Print Manager Printing Solution for Any Web Platform

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Buy Printer Emulator SDKs

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Buy Virtual Printer Drivers

Virtual ZPL Printer Driver Convert, Print, Preview & Render ZPL

Buy On-Premise Web APIs for Docker

How to print multiple files to client printers from ASP.NET

Overview

Requirements

Development/Server-side

Client-side

Follow up these steps

Creating/Editing Controllers

Creating/Editing Views

Be sure this View links to jQuery 1.4.1+ file!

Creating/Editing Controllers

Creating/Editing Views

Be sure this View links to jQuery 1.4.1+ file!

Creating/Editing Controllers

Creating/Editing Views

Be sure this View links to jQuery 1.4.1+ file!

Creating/Editing Controllers

Creating SPA by using AngularJS

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

Creating HTTP Handlers

Creating/Editing WebForm Pages

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

Creating HTTP Handlers

Creating/Editing WebForm Pages

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

Useful? Share it!

Related Articles

Need help? Contact Support

Barcode Professional
Encoder / Writer / Generator

ThermalLabel
Design & Print Barcode Thermal Labels

JS Print Manager
Printing Solution for Any Web Platform

WebClientPrint
RAW & File Printing for ASP.NET & PHP

ZPL Printer Emulator SDK
Convert, Preview & Render ZPL to Image & PDF

EPL Printer Emulator SDK
Convert, Preview & Render EPL to Image & PDF

Virtual ZPL Printer Driver
Convert, Print, Preview & Render ZPL

Barcode Professional
Encoder / Writer / Generator

ThermalLabel
Design & Print Barcode Thermal Labels

JS Print Manager
Printing Solution for Any Web Platform

WebClientPrint
RAW & File Printing for ASP.NET & PHP

ZPL Printer Emulator SDK
Convert, Preview & Render ZPL to Image & PDF

EPL Printer Emulator SDK
Convert, Preview & Render EPL to Image & PDF

Virtual ZPL Printer Driver
Convert, Print, Preview & Render ZPL

Barcode Professional
Encoder / Writer / Generator

ThermalLabel
Design & Print Barcode Thermal Labels

ZPL Printer Emulator SDK
Convert, Preview & Render ZPL to Image & PDF

JS Print Manager
Printing Solution for Any Web Platform

WebClientPrint
RAW & File Printing for ASP.NET & PHP

Barcode Professional
Encoder / Writer / Generator

ThermalLabel
Design & Print Barcode Thermal Labels

JS Print Manager
Printing Solution for Any Web Platform

WebClientPrint
RAW & File Printing for ASP.NET & PHP

ZPL Printer Emulator SDK
Convert, Preview & Render ZPL to Image & PDF

EPL Printer Emulator SDK
Convert, Preview & Render EPL to Image & PDF

Virtual ZPL Printer Driver
Convert, Print, Preview & Render ZPL