发送原始数据打印不工作

Question

我想发送原始数据进行打印，避免选择打印机（快速打印）。

我正在尝试使用微软提供的这个助手：https://support.microsoft.com/en-us/kb/322091#top

但是，当我调用该方法时：

RawPrinterHelper.SendStringToPrinter(pd.PrinterSettings.PrinterName, s);

我的打印机开始工作（发出一些噪音），但它从不拿白纸开始打印。

我已经用我的两台打印机进行了尝试，两台打印机的行为都是一样的。我也放弃了打印机坏掉的可能性，因为我可以打印其他文件。

有什么问题？

Answer 1

试试这个：

using System;
using System.Drawing;
using System.Drawing.Printing;
using System.IO;
using System.Runtime.InteropServices;
using System.Windows.Forms;

public class RawPrinterHelper
{
  // Structure and API declarions:
  [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
  public class DOCINFOA
  {
    [MarshalAs(UnmanagedType.LPStr)] public string pDocName;
    [MarshalAs(UnmanagedType.LPStr)] public string pOutputFile;
    [MarshalAs(UnmanagedType.LPStr)] public string pDataType;
  }
  [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 );

  // SendBytesToPrinter()
  // When the function is given a printer name and an unmanaged array
  // of bytes, the function sends those bytes to the print queue.
  // Returns true on success, false on failure.
  public static bool SendBytesToPrinter( string szPrinterName, IntPtr pBytes, Int32 dwCount)
  {
    Int32    dwError = 0, dwWritten = 0;
    IntPtr    hPrinter = new IntPtr(0);
    DOCINFOA    di = new DOCINFOA();
    bool    bSuccess = false; // Assume failure unless you specifically succeed.
    di.pDocName = "My C#.NET RAW Document";
    di.pDataType = "RAW";

    // Open the printer.
    if( OpenPrinter( szPrinterName.Normalize(), out hPrinter, IntPtr.Zero ) )
    {
      // Start a document.
      if( StartDocPrinter(hPrinter, 1, di) )
      {
        // Start a page.
        if( StartPagePrinter(hPrinter) )
        {
          // Write your bytes.
          bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
          EndPagePrinter(hPrinter);
        }
        EndDocPrinter(hPrinter);
      }
      ClosePrinter(hPrinter);
    }
    // If you did not succeed, GetLastError may give more information
    // about why not.
    if( bSuccess == false )
    {
      dwError = Marshal.GetLastWin32Error();
    }
    return bSuccess;
  }

  public static bool SendFileToPrinter( string szPrinterName, string szFileName )
  {
    // Open the file.
    FileStream fs = new FileStream(szFileName, FileMode.Open);
    // Create a BinaryReader on the file.
    BinaryReader br = new BinaryReader(fs);
    // Dim an array of bytes big enough to hold the file's contents.
    Byte []bytes = new Byte[fs.Length];
    bool bSuccess = false;
    // Your unmanaged pointer.
    IntPtr pUnmanagedBytes = new IntPtr(0);
    int nLength;

    nLength = Convert.ToInt32(fs.Length);
    // Read the contents of the file into the array.
    bytes = br.ReadBytes( nLength );
    // Allocate some unmanaged memory for those bytes.
    pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
    // Copy the managed byte array into the unmanaged array.
    Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
    // Send the unmanaged bytes to the printer.
    bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
    // Free the unmanaged memory that you allocated earlier.
    Marshal.FreeCoTaskMem(pUnmanagedBytes);
    return bSuccess;
  }

  public static bool SendStringToPrinter( string szPrinterName, string szString )
  {
    IntPtr pBytes;
    Int32 dwCount;

    // How many characters are in the string?
    // Fix from Nicholas Piasecki:
    // dwCount = szString.Length;
    dwCount = (szString.Length + 1) * Marshal.SystemMaxDBCSCharSize;

    // Assume that the printer is expecting ANSI text, and then convert
    // the string to ANSI text.
    pBytes = Marshal.StringToCoTaskMemAnsi(szString);
    // Send the converted ANSI string to the printer.
    SendBytesToPrinter(szPrinterName, pBytes, dwCount);
    Marshal.FreeCoTaskMem(pBytes);
    return true;
  }
}

Answer 2

Fran_gg7，我最近遇到了同样的问题。首先，在打印机上开启文档的持久化。这将允许您查看打印机是否成功接收到打印请求。

您将看到打印机队列中的项目，它们将保留在那里。

在我的场景中，打印请求被正确发送到打印机，但是我在激光打印机上测试它，最终无法解释我传递给它的原始字符串数据。

我在可以理解 ZPL（斑马编程语言）的标签打印机上测试了相同的输出，我通过了它，并且运行良好。

查看此详细信息explanation

希望这会有所帮助。

Answer 3

如果您使用此处 https://support.microsoft.com/en-us/kb/322091#top 的 MSDN 示例，但尝试使用字节数组而不是字符串或文件...这可能会有所帮助

public static void SendBytesToLocalPrinter(byte[] data, string printerName)
{
   var size = Marshal.SizeOf(data[0]) * data.Length;
   var pBytes = Marshal.AllocHGlobal(size);
   try
   {
      SendBytesToPrinter(printerName, pBytes, size);
   }
   finally
   {
      Marshal.FreeCoTaskMem(pBytes);
   }
}

这不会随着字节数组编码而改变。如果您尝试发送一些 utf8 编码的字节序列，其中混合了一些二进制（即图像）数据，这很有用，就像我们团队的情况一样。

Answer 4

如果使用“RawPrinterHelper”方法将纯文本打印到点阵，只有当我手动添加打印机、选择通用/纯文本并选择分配给我的 USB 连接打印机的 USB001 端口时，它才能正常工作（ okidata 在我的测试中）。然后 RawPrinterHelper.SendStringToPrinter 会表现得非常像'lpd to lpt1:'

Answer 5

我的 ZEBRA ZD420 打印机也有同样的问题。 发送 ZPL 字符串到打印机，只是数据灯快闪，没有打印。

我只是改变了

Marshal.StringToCoTaskMemAnsi(szString);
to 
Marshal.StringToCoTaskMemUTF8(szString);

它有效！