打印原始数据时缩放文档

Question

我正在尝试直接在打印机上打印pdf文件，它支持postscript。不幸的是，打印文档被缩放（比adobe reader的打印小一点，缩放模式 - “实际大小”）。有没有办法打印它没有缩放？这是一个我用来打印的代码：

  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Interoperability", "CA1401:PInvokesShouldNotBeVisible"), DllImport("winspool.Drv", EntryPoint = "OpenPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall, ThrowOnUnmappableChar = true, BestFitMapping = false)]
    public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd);

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Interoperability", "CA1401:PInvokesShouldNotBeVisible"), DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern bool ClosePrinter(IntPtr hPrinter);

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Interoperability", "CA1401:PInvokesShouldNotBeVisible"), DllImport("winspool.Drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall, ThrowOnUnmappableChar = true, BestFitMapping = false)]
    public static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Interoperability", "CA1401:PInvokesShouldNotBeVisible"), DllImport("winspool.Drv", EntryPoint = "EndDocPrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern bool EndDocPrinter(IntPtr hPrinter);

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Interoperability", "CA1401:PInvokesShouldNotBeVisible"), DllImport("winspool.Drv", EntryPoint = "StartPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern bool StartPagePrinter(IntPtr hPrinter);

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Interoperability", "CA1401:PInvokesShouldNotBeVisible"), DllImport("winspool.Drv", EntryPoint = "EndPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern bool EndPagePrinter(IntPtr hPrinter);

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Interoperability", "CA1401:PInvokesShouldNotBeVisible"), 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 static bool SendFileToPrinter(string pdfFileName, string printerName, string name)
    {
        try
        {
            bool success = false;
            using (FileStream fs = new FileStream(pdfFileName, FileMode.Open))
            {
                int nLength = Convert.ToInt32(fs.Length);

                BinaryReader br = new BinaryReader(fs);

                Byte[] bytes = new Byte[fs.Length];
                bytes = br.ReadBytes(nLength);

                IntPtr ptrUnmanagedBytes = new IntPtr(0);
                ptrUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);

                Marshal.Copy(bytes, 0, ptrUnmanagedBytes, nLength);

                success = SendBytesToPrinter(printerName, ptrUnmanagedBytes, nLength, name);

                Marshal.FreeCoTaskMem(ptrUnmanagedBytes);
            }
            return success;
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }


    private static bool SendBytesToPrinter(string szPrinterName, IntPtr pBytes, Int32 dwCount, string name)
    {
        try
        {
            Int32 dwError = 0, dwWritten = 0;
            IntPtr hPrinter = new IntPtr(0);
            DOCINFOA di = new DOCINFOA();
            bool success = false; // Assume failure unless you specifically succeed.

            di.pDocName = name;
            di.pDataType = "RAW";

            if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero))
            {
                if (StartDocPrinter(hPrinter, 1, di))
                {
                    if (StartPagePrinter(hPrinter))
                    {
                        success = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
                        EndPagePrinter(hPrinter);
                    }
                    EndDocPrinter(hPrinter);
                }
                ClosePrinter(hPrinter);
            }

            if (success == false)
            {
                dwError = Marshal.GetLastWin32Error();
            }
            return success;
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }

顺便说一下 - 当我这样打印时，我可以管理打印机页边距吗？

谢谢，巴托斯

Answer 1

PDF和PostScript不是一回事！仅仅因为您的打印机“支持PostScript”并不意味着它可以打印PDF文件。

在这种情况下，它看起来确实像您的打印机支持PDF打印。为缩放输出而考虑的原因有两个：

1）PDF文件的介质尺寸与打印机中的介质不匹配。

2）打印机具有不可打印的边距。为了确保打印整个PDF文件（如果它包含直到介质边缘的绘图操作），打印机将缩放PDF以使PDF介质适合打印介质的可打印区域。

您可以根据打印机中的介质检查PDF页面的介质尺寸。如果他们匹配那么你知道它不是那个。

解决方案完全取决于打印机的功能。您可以告诉它不要缩放输出（如果您确定PDF的标记区域将适合打印页面的可打印区域）。如果没有，那么您唯一的解决方案是使用较小的媒体重制PDF文件。

您还可以尝试在PDF文件中设置一个小于打印介质的CropBox，然后查看您的打印机是否会打印未缩放的PDF。

Answer 2

感谢@KenS的建议，最后我找到了一个解决方案，为什么PDF打印不正确。默认PDF缩放存在问题，即尝试将打印适合页面。解决方案是设置缩放：

/ViewerPreferences<</PrintScaling/None>> 

在PDF文件中，例如：

对象之前：

2 0 obj
<<
/Type/Catalog
/Pages 3
>>
endobj

对象后：

2 0 obj
<<
/Type/Catalog
/ViewerPreferences<</PrintScaling/None>>
/Pages 3
>>
endobj