我将从一段历史开始：我目前遇到的问题突然出现而没有对代码进行任何更改。然后在3天后以同样的方式消失。现在它在一周后回来了，不想离开=）。
我有适用于打印机的代码 - 设置打印机首选项以指定方式打印文档。我使用本地打印机指向网络打印机的TCP地址（这是我所知的任务的常用方法）。
下面是用于从二进制文件加载打印机配置的代码（以前以类似的方式保存）。我给所有源代码提供了非托管函数调用的声明，因为不知道是什么原因导致了这个问题。制动我的应用程序的行（Windows服务）：
Marshal.StructureToPtr(pInfo, pPInfo, true); //THIS LINE FAILS
这是函数的整个代码：
public static bool LoadSettings(string printerName, string filepath)
{
Logger.GetLog().WriteInformation(string.Format("Loading printer settings '{0}' for printer '{1}'", filepath, printerName), "PrinterSettingsStorage.LoadSettings()");
bool success = false;
try
{
if (!File.Exists(filepath))
{
return false;
}
IntPtr hPrinter;
int bytes = 0;
IntPtr pPInfo;
IntPtr pDevMode;
PRINTER_INFO_2 pInfo = new PRINTER_INFO_2();
PRINTER_DEFAULTS PrinterValues = new PRINTER_DEFAULTS();
PrinterValues.pDatatype = 0;
PrinterValues.pDevMode = 0;
PrinterValues.DesiredAccess = PRINTER_ALL_ACCESS;
//retrieve the devmode from file
using (FileStream fs = new FileStream(filepath, FileMode.Open))
{
int length = Convert.ToInt32(fs.Length);
pDevMode = GlobalAlloc(0, length);
for (int i = 0; i < length; i++)
{
Marshal.WriteByte(pDevMode, i, (byte)fs.ReadByte());
}
}
//get printer handle
OpenPrinter(printerName, out hPrinter, ref PrinterValues);
//get bytes for printer info structure and allocate memory
GetPrinter(hPrinter, 2, IntPtr.Zero, 0, out bytes);
if (bytes == 0)
{
throw new Exception("Get Printer Failed");
}
pPInfo = GlobalAlloc(0, bytes);
//set pointer to printer info
GetPrinter(hPrinter, 2, pPInfo, bytes, out bytes);
//place the printer info structure
pInfo = (PRINTER_INFO_2)Marshal.PtrToStructure(pPInfo, typeof(PRINTER_INFO_2));
//insert the new devmode
pInfo.pDevMode = pDevMode;
pInfo.pSecurityDescriptor = IntPtr.Zero;
//set pointer to new printer info
Marshal.StructureToPtr(pInfo, pPInfo, true); //THIS LINE FAILS
//update
SetPrinter(hPrinter, 2, pPInfo, 0);
//free resources
GlobalFree(pPInfo);
GlobalFree(pDevMode);
ClosePrinter(hPrinter);
success = true;
}
catch (COMException ce)
{
Logger.GetLog().WriteError(string.Format("COM error loading printer settings to printer: {0}", Marshal.GetLastWin32Error()), ce.StackTrace, "PrinterSettingsStorage.LoadSettings()");
}
catch (Exception e)
{
Logger.GetLog().WriteError(string.Format("Unknown error loading printer settings to printer"), e.StackTrace, "PrinterSettingsStorage.LoadSettings()");
}
finally
{
Logger.GetLog().WriteInformation(string.Format("Finish loading printer settings '{0}' for printer '{1}'. Success: {2}", printerName, filepath, success), "PrinterSettingsStorage.LoadSettings()");
}
return success;
}
[StructLayout(LayoutKind.Sequential)]
internal struct PRINTER_DEFAULTS
{
public int pDatatype;
public int pDevMode;
public int DesiredAccess;
}
[StructLayout(LayoutKind.Sequential)]
internal struct PRINTER_INFO_2
{
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pServerName;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pPrinterName;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pShareName;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pPortName;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pDriverName;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pComment;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pLocation;
public IntPtr pDevMode;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pSepFile;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pPrintProcessor;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pDatatype;
[MarshalAs(UnmanagedType.LPStr)]
public readonly string pParameters;
public IntPtr pSecurityDescriptor;
public readonly Int32 Attributes;
public readonly Int32 Priority;
public readonly Int32 DefaultPriority;
public readonly Int32 StartTime;
public readonly Int32 UntilTime;
public readonly Int32 Status;
public readonly Int32 cJobs;
public readonly Int32 AveragePPM;
}
[DllImport("kernel32.dll", ExactSpelling = true)]
private static extern IntPtr GlobalFree(IntPtr handle);
[DllImport("winspool.Drv", EntryPoint = "GetPrinterA", SetLastError = true,
CharSet = CharSet.Ansi, ExactSpelling = true,
CallingConvention = CallingConvention.StdCall)]
private static extern bool GetPrinter(IntPtr hPrinter, Int32 dwLevel,
IntPtr pPrinter, Int32 dwBuf, out Int32 dwNeeded);
[DllImport("winspool.Drv", EntryPoint = "OpenPrinterA",
SetLastError = true, CharSet = CharSet.Ansi,
ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
private static extern bool
OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter,
out IntPtr hPrinter, ref PRINTER_DEFAULTS pd);
[DllImport("winspool.drv", CharSet = CharSet.Ansi, SetLastError = true)]
private static extern bool SetPrinter(IntPtr hPrinter, int Level, IntPtr pPrinter, int Command);
[DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true,
ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
private static extern bool ClosePrinter(IntPtr hPrinter);
症状：
服务只是立即停止在参考线上退出。没有最终的块执行，没有异常被捕获。
Windows事件日志包含错误
错误模块名称：ntdll.dll，版本：6.1.7601.17725，时间戳：0x4ec49b8f 异常代码：0xc0000374 故障偏移：0x000ce6c3 错误进程id：0x12dc 错误应用程序启动时间：0x01cdc71b9bf9b661 错误的应用程序路径：C：\ Program Files（x86）\ MyServiceExePath.exe 错误模块路径：C：\ Windows \ SysWOW64 \ ntdll.dll 报告编号：0eb45111-330f-11e2-be8e-005056975a30
我的操作系统：Windows Server 2008 R2。
正如我所说，它会在一段时间内不断重现，然后一旦离开而没有任何代码更改。我不知道是什么导致了这个问题，为什么它如此不稳定。希望这里有人，对我的非托管代码更加满意=）。
有什么想法吗？
答案 0 :(得分：0)
//insert the new devmode
pInfo.pDevMode = pDevMode;
pInfo.pSecurityDescriptor = IntPtr.Zero;
//Add by me
Marshal.StructureToPtr(pInfo, pPInfo, false);
//set pointer to new printer info
Marshal.StructureToPtr(pInfo, pPInfo, true);
//update
SetPrinter(hPrinter, 2, pPInfo, 0);
//Add by me
Marshal.DestroyStructure(pPInfo, typeof(PRINTER_INFO_2));
//free resources
GlobalFree(pPInfo);
GlobalFree(pDevMode);
ClosePrinter(hPrinter);