Question

我正在构建一个程序来捕获打印的文档，然后将这些文档转换为xps \ image。

目前我使用FileSystemWatcher来监控目录“C：\ Windows \ System32 \ spool \ PRINTERS \”并复制spl文件，确保其不重复，然后尝试转换通过使用Win32 Spooler API和 Microsoft XPS Document Writer 预定义打印机打印spl文件到xps文件，但是当我指定如下所示的输出文件时，返回错误代码1804，如果我把它留空是成功但是我没有得到输出文件。

    public static bool SendBytesToPrinter(string szPrinterName, IntPtr pBytes, Int32 dwCount, string outputFile, string dataType, out int errorCode)
    {
        IntPtr hPrinter;
        var di = new DOCINFOA();
        var bSuccess = false; // Assume failure unless you specifically succeed.

        di.pDocName = "Spool Doc";
        di.pDataType = dataType;
        di.pOutputFile = outputFile;

        // 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.
                    var dwWritten = 0;
                    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.
        errorCode = bSuccess == false ? Marshal.GetLastWin32Error() : 0;
        return bSuccess;
    }

那么，我做错了什么，以及如何打印\将假脱机文件转换为XPS文档，如果可能的话，转换为图像文件和文本文件。

修改：添加其他信息

这是DOCINFOA的实现

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

这是完整的调用链：

该应用运行以下代码

    var dataTypes = new[] { null, "RAW", "RAW [FF appended]", "RAW [FF auto]", "NT EMF 1.003", "NT EMF 1.006", "NT EMF 1.007", "NT EMF 1.008", "TEXT", "XPS_PASS", "XPS2GDI" };
    foreach (var dataType in dataTypes)
    {
        int errorCode;
        RawPrinterHelper.SendFileToPrinter(@"Microsoft XPS Document Writer", sourceFile, outputFile, dataType, out errorCode);
        //print errorCode
    }

在 RawPrinterHelper

中

    public static bool SendFileToPrinter(string szPrinterName, string szFileName, string outputPath, string dataType, out int errorCode)
    {
        // Open the file.
        var fs = new FileStream(szFileName, FileMode.Open);
        // Create a BinaryReader on the file.
        var br = new BinaryReader(fs);
        // Dim an array of bytes big enough to hold the file's contents.
        // Your unmanaged pointer.
        var documentPath = Path.GetFileName(szFileName);
        var nLength = Convert.ToInt32(fs.Length);
        // Read the contents of the file into the array.
        var bytes = br.ReadBytes(nLength);
        // Allocate some unmanaged memory for those bytes.
        var 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.
        var bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength, outputPath, dataType, out errorCode);
        // Free the unmanaged memory that you allocated earlier.
        Marshal.FreeCoTaskMem(pUnmanagedBytes);
        fs.Close();
        return bSuccess;
    }

API函数

    [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);

Answer 1

问题是您对DOC_INFO_1结构的声明。它与the layout Windows expects不匹配。 Windows声明如下所示：

typedef struct _DOC_INFO_1 {
  LPTSTR pDocName;
  LPTSTR pOutputFile;
  LPTSTR pDatatype;
} DOC_INFO_1;

但你的声明是这样的：

public class DOCINFOA
{
    public string pDataType;
    public string pDocName;
    public string pOutputFile;
}

重新排序声明中的元素以匹配Windows结构，它应该可以解决您的问题。

编辑：坏消息。你的方法不起作用。请查看WritePrinter的文档：

WritePrinter仅支持GDI打印，不得用于XPS 打印。如果您的打印作业使用XPS或OpenXPS打印路径， then use the XPS Print API。将XPS或OpenXPS打印作业发送到不支持使用WritePrinter的假脱机程序，可能会导致未确定的结果。

如何使用XPS打印机重新打印假脱机文件？

1 个答案: