在C#中打印pcl文件不起作用，有什么建议吗？

Question

我正在尝试使用C#编程打印PCL文件。我参考了微软的以下链接（注意是VB语言）：http://support.microsoft.com/kb/298141。但不幸的是，它并没有起作用...我只得到了空白页面。请注意，如果我只是从提示符中将PCL文件复制到打印机上，即复制文件名 打印机。页面就会被正确地打印。有什么建议吗？

public class PrintRaw
  {
    [StructLayout(LayoutKind.Sequential)]
    public class DocInfo
    {
      [MarshalAs(UnmanagedType.LPWStr)] public String docName;
      [MarshalAs(UnmanagedType.LPWStr)] public String outputFile;
      [MarshalAs(UnmanagedType.LPWStr)] public String dataType;
    }

    [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)] DocInfo 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);

    public void Print(String printerName, String filename)
    {
      IntPtr lhPrinter;
      OpenPrinter(printerName, out lhPrinter, new IntPtr(0));

      if (lhPrinter.ToInt32() == 0)
        return; //Printer not found!!

      var rawPrinter = new DocInfo() {docName = "My Document", dataType = "RAW"};

      StartDocPrinter(lhPrinter, 1, rawPrinter);

      using (var b = new BinaryReader(File.Open(filename, FileMode.Open)))
      {
        var length = (int) b.BaseStream.Length;
        const int bufferSize = 8192;

        var numLoops = length/bufferSize;
        var leftOver = length%bufferSize;


        for (int i = 0; i < numLoops; i++)
        {
          var buffer = new byte[bufferSize];
          int dwWritten;

          b.Read(buffer, 0, bufferSize);
          IntPtr unmanagedPointer = Marshal.AllocHGlobal(buffer.Length);
          Marshal.Copy(buffer, 0, unmanagedPointer, buffer.Length);
          WritePrinter(lhPrinter, unmanagedPointer, bufferSize, out dwWritten);
          Marshal.FreeHGlobal(unmanagedPointer);
        }

        if (leftOver > 0)
        {
          var buffer = new byte[leftOver];
          int dwWritten;

          b.Read(buffer, 0, leftOver);
          IntPtr unmanagedPointer = Marshal.AllocHGlobal(buffer.Length);
          Marshal.Copy(buffer, 0, unmanagedPointer, buffer.Length);
          WritePrinter(lhPrinter, unmanagedPointer, leftOver, out dwWritten);
          Marshal.FreeHGlobal(unmanagedPointer);
        }
      }

      EndDocPrinter(lhPrinter);
      ClosePrinter(lhPrinter);
    }
  }

- vicsz

---

由于某种原因，调用StartDocPrinter失败，Win32错误代码为1804，数据类型无效。 - vicsz

以下是你在顶部引用代码的C#版本链接：http://support.microsoft.com/kb/322091 - Douglas Anderson

Answer 1

好的，看起来我在示例中使用的数据类型是无效的。我已将其更新为以下内容（请注意设置Charset），并解决了问题。

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public class DOC_INFO_1
{
  [MarshalAs(UnmanagedType.LPStr)]
  public string pDocName;
  [MarshalAs(UnmanagedType.LPStr)]
  public string pOutputFile;
  [MarshalAs(UnmanagedType.LPStr)]
  public string pDataType;
}

- vicsz