How to print raw TSC TSPL/TSPL2 commands from Blazor

Product JSPrintManager for Blazor Published 05/14/2025 Updated 05/14/2025 Author

Overview

TSPL (TSC Printer Language) commands are a set of instructions used to control a thermal label printer, enabling the creation of various types of labels and other printed materials. These commands are used to define the layout, text, graphics, and other elements of the label.

Basic TSPL commands for some printing elements include:

  • SIZE: Set the size of the label in inch unit.
  • PRINT: Prints the label n times/copies.
  • TEXT: Prints text on the label, allowing for font selection, size, and position control.
  • BARCODE: Prints various types of 1D and 2D barcodes, including their type, size, and position.
  • QRCODE: Prints QR codes, allowing for encoding data within a label.
  • BITMAP: Prints bitmap images, enabling the inclusion of graphics on labels.
  • IMAGE: Another command for printing images, often used in conjunction with the BITMAP command.

TSC TSPL/TSPL2 commands are very simple and text plain! The main advantage of using raw TSC TSPL/TSPL2 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. You'll be able to use raw printing feature with the help of our JSPrintManager for Blazor solution that was specially designed for this kind of printing needs.

In this walkthrough, you'll learn how to print raw FGL commands from Blazor directly to the client printer without displaying a print dialog at all. You'll be able to print TSC TSPL/TSPL2 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, IE/Edge & Safari on Windows, Linux, Raspberry Pi and Mac systems!

The TSC TSPL/TSPL2 commands that we'll use in this article will print out a ticket passport that will look like this:

A Sample Label printed from Blazor and created by using TSC TSPL/TSPL2 commands
A Sample label printed from Blazor and created by using TSC TSPL/TSPL2 commands

Follow up these steps

  • Be sure you install in your dev machine JSPrintManager (JSPM) (Available for Windows, Linux, Raspberry Pi & Mac)
    This small app must be installed on each client that will print from your website!
  • In your Blazor project...
    • Add a NuGet reference to the JSPrintManager Razor Component
    • Add the JSPrintManager service...
      • Add the following statement at the top of your Startup file
        using Neodynamic.Blazor;
        • For Blazor Server
          Add the following line in the Startup's ConfigureServices method
          services.AddJSPrintManager();
          For .NET 8+ you must use Interactive Server components and render mode, so add these settings:
          
    builder.Services.AddRazorComponents()
    .AddInteractiveServerComponents();
     
          
    app.MapRazorComponents<App>()
    .AddInteractiveServerRenderMode()
        • For Blazor WebAssembly
          Add the following line in the Program's Main method
          builder.Services.AddJSPrintManager();
    • Add the following statement in the _Imports.razor file
      @using Neodynamic.Blazor
    • Add a new Razor Page and copy/paste the following code. Please read the source code comments to understand the printing logic!
      For .NET 8+ Blazor Server you must use Interactive Server render mode, so add these settings:
      
@page "/"
@rendermode InteractiveServer
@inject JSPrintManager JSPrintManager

      
@page "/"
@inject JSPrintManager JSPrintManager

<div>
    <strong>JSPM </strong><span>WebSocket Status </span>

    @if (JSPrintManager.Status == JSPMWSStatus.Open)
    {
        <span class="badge badge-success">
            <i class="fa fa-check" /> Open
        </span>
    }
    else if (JSPrintManager.Status == JSPMWSStatus.Closed)
    {
        <span class="badge badge-danger">
            <i class="fa fa-exclamation-circle" /> Closed!
        </span>
        <div>
            <strong>JSPrintManager (JSPM) App</strong> is not installed or not running! <a href="https://neodynamic.com/downloads/jspm" target="_blank">Download JSPM Client App...</a>
        </div>
    }
    else if (JSPrintManager.Status == JSPMWSStatus.Blocked)
    {
        <span class="badge badge-warning">
            <i class="fa fa-times-circle" /> This Website is Blocked!
        </span>
    }
    else if (JSPrintManager.Status == JSPMWSStatus.WaitingForUserResponse)
    {
        <span class="badge badge-warning">
            <i class="fa fa-user-circle" /> Waiting for user response...
        </span>
    }
</div>

@if (JSPrintManager.Status == JSPMWSStatus.Open)
{
    @if (JSPrintManager.Printers == null)
    {
        <hr />
        <div class="spinner-border text-info" role="status">
            <span class="sr-only">Please wait...</span>
        </div>
        <strong><em>Getting local printers...</em></strong>
    }
    else
    {
        <div>
            <h1>Print TSC TSPL/TSPL2 commands from Blazor</h1>
            <hr />
            <EditForm Model="@MyPrinter">
                <div class="form-check">
                    <InputCheckbox class="form-check-input" @bind-Value="UseDefaultPrinter" />Print to <strong>Default Printer?</strong><br />
                </div>
                <p>or...</p>
                <p>Select an <strong>Installed Printer</strong>:</p>
                <InputSelect @bind-Value="MyPrinter.PrinterName" class="form-control form-control-sm">
                    @foreach (var p in JSPrintManager.Printers)
                            {
                        <option value="@p">@p</option>
                            }
                </InputSelect>
            </EditForm>
            <br /><br />
                  <input type="button" value="Print Now..." @onclick="DoPrint" />
        </div>
    }
}


@code {

    // An Installed Printer instance
    private InstalledPrinter MyPrinter { get; set; } = new();
    // Use default printer?
    private bool UseDefaultPrinter = false;

    // Printing...
    private void DoPrint()
    {
        // Status = Open means that JSPM Client App is up and running!
        if (JSPrintManager.Status == JSPMWSStatus.Open)
        {
            // Create a ClientPrintJob
            var cpj = new ClientPrintJob();
            // Set target Printer
            cpj.ClientPrinter = UseDefaultPrinter ? new DefaultPrinter() : MyPrinter;
            // Create TSC TSPL/TSPL2 commands for sample label

            var lineFeed = "\r\n";

            var cmds = '';
            cmds += "SIZE 4,1";
            cmds += lineFeed;
            cmds += "GAP 0,0";
            cmds += lineFeed;
            cmds += "DIRECTION 1";
            cmds += lineFeed;
            cmds += "CLS";
            cmds += lineFeed;
            cmds += "TEXT 10,10, \"2\",0,1,1, \"Code 128\"";
            cmds += lineFeed;
            cmds += "BARCODE 10,50, \"128\",100,1,0,2,2, \"123456abcd123456\"";
            cmds += lineFeed;
            cmds += "PRINT 1";

            // Set the RAW commands to send to the printer...
            cpj.PrinterCommands = cmds;
            // PRINT IT!!!
            JSPrintManager.SendClientPrintJob(cpj);
        }
    }

    protected override void OnAfterRender(bool firstRender)
    {
        if (firstRender)
        {
            // Handle OnGetPrinters event...
            JSPrintManager.OnGetPrinters += () =>
            {
                if (JSPrintManager.Printers != null &&
                    JSPrintManager.Printers.Length > 0)
                {
                    // Display installed printers...
                    StateHasChanged();
                }
                else
                {
                    Console.WriteLine("No printers found...");
                }

            };

            // Handle OnStatusChanged event to detect any WSS status change
            JSPrintManager.OnStatusChanged += () =>
            {
                StateHasChanged();

                // Status = Open means that JSPM Client App is up and running!
                if (JSPrintManager.Status == JSPMWSStatus.Open)
                {
                    //Try getting local printers...
                    JSPrintManager.TryGetPrinters();
                }
            };

            // Start WebSocket comm
            JSPrintManager.Start();
        }

        base.OnAfterRender(firstRender);
    }
}
  • That's it! Run your website and test it. Click on Print Now... to print the TSC TSPL/TSPL2 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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