如何通过 USB 使用 C# 将原始 ZPL 发送到 zebra 打印机

Question

我是初学者 C# 程序员。 我有一个项目需要我通过 USB 将原始命令发送到 Zebra 打印机 LP 2844 并使其工作。 我做了很多研究，并试图找到一种方法来做到这一点。 我正在使用来自http://support.microsoft.com/kb/322091的代码，但它没有用。 根据我的测试，我似乎已经向打印机发送了命令，但它没有响应并打印。 我不知道这个。 有人可以帮我吗？

我正在使用按钮直接发送命令

private void button2_Click(object sender, EventArgs e)
{
    string s = "A50,50,0,2,1,1,N,\"9129302\"";

    // Allow the user to select a printer.
    PrintDialog pd = new PrintDialog();
    pd.PrinterSettings = new PrinterSettings();
    if (DialogResult.OK == pd.ShowDialog(this))
    {
        // Send a printer-specific to the printer.
        RawPrinterHelper.SendStringToPrinter(pd.PrinterSettings.PrinterName, s);
        MessageBox.Show("Data sent to printer.");
    }
}

Answer 1

编辑：为了解决您的更新，您遇到的问题是您正在使用SendStringToPrinter ，它将 ANSI 字符串（空终止）字符串发送到打印机，这不是打印机所期望的。 根据官方EPL2 编程指南第 23 页（根据您的示例，这是您真正在做什么，而不是 ZPL）。

每个命令行必须以换行 (LF) 字符（12 月 10 日）结束。 大多数基于 PC 的系统在按下 Enter 键时发送 CR/LF。 回车 (CR) 字符被打印机忽略，不能代替 LF。

因此，您必须修改SendStringToPrinter以在字符串末尾发送\\n而不是\\0或者您必须自己构建 ASCII 字节数组并自己使用RawPrinterHelper.SendBytesToPrinter （就像我在下面的原始答案中所做的那样）。

因此，为了修复您发布的简单示例，我们更改了您的函数调用，我们还必须通过发送P1\\n来告诉打印机实际打印P1\\n

private void button2_Click(object sender, EventArgs e)
{
    string s = "A50,50,0,2,1,1,N,\"9129302\"\n";
    s += "P1\n";

    // Allow the user to select a printer.
    PrintDialog pd = new PrintDialog();
    pd.PrinterSettings = new PrinterSettings();
    if (DialogResult.OK == pd.ShowDialog(this))
    {
        var bytes = Encoding.ASCII.GetBytes(s);
        // Send a printer-specific to the printer.
        RawPrinterHelper.SendBytesToPrinter(pd.PrinterSettings.PrinterName, bytes, bytes.Length);
        MessageBox.Show("Data sent to printer.");
    }
}

//elsewhere
public static class RawPrinterHelper
{
    //(Snip) The rest of the code you already have from http://support.microsoft.com/kb/322091

    [DllImport("winspool.Drv", EntryPoint="WritePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool WritePrinter(IntPtr hPrinter, byte[] pBytes, Int32 dwCount, out Int32 dwWritten );


    private static bool SendBytesToPrinter(string szPrinterName, byte[] bytes, Int32 dwCount)
    {
        Int32 dwError = 0, dwWritten = 0;
        IntPtr hPrinter = new IntPtr(0);
        DOCINFOA di = new DOCINFOA();
        bool bSuccess = false;

        di.pDocName = "Zebra Label";
        di.pDataType = "RAW";


        if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero))
        {
            if (StartDocPrinter(hPrinter, 1, di))
            {
                if (StartPagePrinter(hPrinter))
                {
                    bSuccess = WritePrinter(hPrinter, bytes, dwCount, out dwWritten);
                    EndPagePrinter(hPrinter);
                }
                EndDocPrinter(hPrinter);
            }
            ClosePrinter(hPrinter);
        }
        if (bSuccess == false)
        {
            dwError = Marshal.GetLastWin32Error();
            throw new Win32Exception(dwError);
        }
        return bSuccess;
    }
}

---

我是用 Zebra 的旧 EPL2 语言完成的，但它应该与您需要用 ZPL 完成的非常相似。 也许它会让你朝着正确的方向开始。

public class Label
{
    #region Print logic. Taken from http://support.microsoft.com/kb/322091

    //Snip stuff unchanged from the KB example.   

    [DllImport("winspool.Drv", EntryPoint="WritePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool WritePrinter(IntPtr hPrinter, byte[] pBytes, Int32 dwCount, out Int32 dwWritten );     

    private static bool SendBytesToPrinter(string szPrinterName, byte[] Bytes, Int32 dwCount)
    {
        Int32 dwError = 0, dwWritten = 0;
        IntPtr hPrinter = new IntPtr(0);
        DOCINFOA di = new DOCINFOA();
        bool bSuccess = false;

        di.pDocName = "Zebra Label";
        di.pDataType = "RAW";


        if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero))
        {
            if (StartDocPrinter(hPrinter, 1, di))
            {
                if (StartPagePrinter(hPrinter))
                {
                    bSuccess = WritePrinter(hPrinter, Bytes, dwCount, out dwWritten);
                    EndPagePrinter(hPrinter);
                }
                EndDocPrinter(hPrinter);
            }
            ClosePrinter(hPrinter);
        }
        if (bSuccess == false)
        {
            dwError = Marshal.GetLastWin32Error();
            throw new Win32Exception(dwError);
        }
        return bSuccess;
    }
    #endregion

    public byte[] CreateCompleteCommand(bool headerAndFooter)
    {
        List<byte> byteCollection = new List<byte>();

        //Static header content describing the label.
        if (headerAndFooter)
        {
            byteCollection.AddRange(Encoding.ASCII.GetBytes("\nN\n"));
            byteCollection.AddRange(Encoding.ASCII.GetBytes(String.Format("S{0}\n", this.Speed)));
            byteCollection.AddRange(Encoding.ASCII.GetBytes(String.Format("D{0}\n", this.Density)));
            byteCollection.AddRange(Encoding.ASCII.GetBytes(String.Format("q{0}\n", this.LabelHeight)));
            if (this.AdvancedLabelSizing)
            {
                byteCollection.AddRange(Encoding.ASCII.GetBytes(String.Format("Q{0},{1}\n", this.LableLength, this.GapLength)));
            }
        }

        //The content of the label.
        foreach (var command in this.Commands)
        {
            byteCollection.AddRange(command.GenerateByteCommand());
        }

        //The footer content of the label.
        if(headerAndFooter)
            byteCollection.AddRange(Encoding.ASCII.GetBytes(String.Format("P{0}\n", this.Pages)));

        return byteCollection.ToArray();
    }

    public bool PrintLabel(string printer)
    {
        byte[] command = this.CreateCompleteCommand(true);
        return SendBytesToPrinter(printer, command, command.Length); 
    }

    public List<Epl2CommandBase> Commands { get; private set; }

    //Snip rest of the code.
}

public abstract partial class Epl2CommandBase
{
    protected Epl2CommandBase() { }

    public virtual byte[] GenerateByteCommand()
    {
        return Encoding.ASCII.GetBytes(CommandString + '\n');
    }
    public abstract string CommandString { get; set; }
}


public class Text : Epl2CommandBase 
{
    public override string CommandString
    {
        get
        {
            string printText = TextValue;
            if (Font == Fonts.Pts24)
                printText = TextValue.ToUpperInvariant();
            printText = printText.Replace("\\", "\\\\"); // Replace \ with \\
            printText = printText.Replace("\"", "\\\""); // replace " with \"
            return String.Format("A{0},{1},{2},{3},{4},{5},{6},\"{7}\"", X, Y, (byte)TextRotation, (byte)Font, HorziontalMultiplier, VertricalMultiplier, Reverse, printText);
        }
        set
        {
            GenerateCommandFromText(value);
        }
    }

    private void GenerateCommandFromText(string command)
    {
        if (!command.StartsWith(GetFactoryKey()))
            throw new ArgumentException("Command must begin with " + GetFactoryKey());
        string[] commands = command.Substring(1).Split(',');
        this.X = int.Parse(commands[0]);
        this.Y = int.Parse(commands[1]);
        this.TextRotation = (Rotation)byte.Parse(commands[2]);
        this.Font = (Fonts)byte.Parse(commands[3]);
        this.HorziontalMultiplier = int.Parse(commands[4]);
        this.VertricalMultiplier = int.Parse(commands[5]);
        this.ReverseImageColor = commands[6].Trim().ToUpper() == "R";
        string message = String.Join(",", commands, 7, commands.Length - 7);
        this.TextValue = message.Substring(1, message.Length - 2); // Remove the " at the beginning and end of the string.
    }

    //Snip
}

Answer 2

如果人们试图从上面的答案中获取该片段：

        [DllImport("winspool.Drv", EntryPoint = "OpenPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd);

        [DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool ClosePrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

        [DllImport("winspool.Drv", EntryPoint = "EndDocPrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool EndDocPrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "StartPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool StartPagePrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "EndPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool EndPagePrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten);

        [DllImport("winspool.Drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true,
            CallingConvention = CallingConvention.StdCall)]
        public static extern bool WritePrinter(IntPtr hPrinter, byte[] pBytes, Int32 dwCount, out Int32 dwWritten);