如何在 WINCE7 C#.net 中将结构指针发送到 DeviceIoControl API

Question

我在WIN CE平台上工作，用C#.Net开发windows窗体。

DeviceIoControl API 与 c++ 控制台应用程序中的参数（如下所述）一起工作正常。

nuiouser.h 中的 PNIC_STATISTICS 结构

  global declarations :
  TCHAR PCI1_NAME[] = _T("PCI\\ManiXX1"); 
  TCHAR *AUB_NAME = NULL;       
  AUB_NAME = PCI1_NAME; 

   pNICStat = (PNIC_STATISTICS)malloc(sizeof(NIC_STATISTICS)) ;

   pNICStat->ptcDeviceName = AUB_NAME ;           //wchar_t* ptcDeviceName 

   DeviceIoControl( hUB94Port,                         //void*
                 IOCTL_NDISUIO_NIC_STATISTICS,
                 pNICStat,                         //PNIC_STATISTICS 
                 0,
                 pNICStat,                        //PNIC_STATISTICS 
                 sizeof(NIC_STATISTICS),
                 &dwReturnedBytes,
                 NULL
               );

但是我在使用 C#.Net CF for WIN-CE7 实现相同的问题时遇到了问题

我的WIN-CE代码如下：

C# 中的修改结构：

    [StructLayout(LayoutKind.Sequential,CharSet = CharSet.Unicode)]
    public struct __NIC_STAT
    {

        ulong Size;               //  Of this structure.

        public Char[] ptcDeviceName;      //  The device name to be queried.. 

        ulong DeviceState;        //  DEVICE_STATE_XXX above
        ulong DeviceState;        //  DEVICE_STATE_XXX above
        ulong MediaType;          //  NdisMediumXXX
        ulong MediaState;         //  MEDIA_STATE_XXX above
        ulong PhysicalMediaType;
        ulong LinkSpeed;          //  In 100bits/s. 10Mb/s = 100000
        UInt64 PacketsSent;
        UInt64 PacketsReceived;
        ulong InitTime;           //  In milliseconds
        ulong ConnectTime;        //  In seconds
        UInt64 BytesSent;          //  0 - Unknown (or not supported)
        UInt64 BytesReceived;      //  0 - Unknown (or not supported)
        UInt64 DirectedBytesReceived;
        UInt64 DirectedPacketsReceived;
        ulong PacketsReceiveErrors;
        ulong PacketsSendErrors;
        ulong ResetCount;
        ulong MediaSenseConnectCount;
        ulong MediaSenseDisconnectCount; 

    } ;

从这个结构中，我只是填写 ptcDeviceName 并尝试发送。

 __NIC_STAT NIC_STAT = new __NIC_STAT();

  Char[] toBytes = {'P','C','I','\\','M','a','n','i','X','X','1','\0'}

  NIC_STAT.ptcDeviceName = toBytes;        //public Char[] ptcDeviceName; in structure 
                                      // __NIC_STAT this is the same structure as 
                                      //in  nuiouser.h     


    int sz = Marshal.SizeOf(NIC_STAT.GetType());//sometimes Getting exception here

     intptr ptr = Marshal.AllocHGlobal(sz);

     Marshal.StructureToPtr((__NIC_STAT)NIC_STAT, ptr, false);

   unsafe 
   {           

         DeviceIoControl(hFileHandle,
                     IOCTL_NDISUIO_NIC_STATISTICS,
                     ref ptr,
                     0,
                     ref ptr,
                     sz,
                     ref dwReturnedBytes,
                     0);
  }//unsafe

对应的原型

  [DllImport("coredll.dll", CharSet = CharSet.Auto, SetLastError = true)]
unsafe public static extern bool DeviceIoControl(
                                                  int hDevice, 
                                                  int dwIoControlCode, 
                                                  ref intptr InBuffer,
                                                  int nInBufferSize,
                                                  ref intptr OutBuffer,
                                                  int nOutputBufferSize, 
                                                  ref int pBytesReturned,
                                                  int pOverlapped
                                                 );

在 Win-CE 中，DeviceIoControl() 失败，出现异常并且不显示任何错误代码。有时会收到错误代码为 87 (INVALID PARAMETERS)。

我觉得 ptcDeviceName 造成了问题，或者可能是因为为指针 (ptr) 分配内存？

在控制台应用程序中，我们将 ptcDeviceName 作为 Wchar_t* 发送，但在 WIN-CE 中，所以我使用了

public Char[] ptcDeviceName;

谁能告诉我哪里做错了？

Answer 1

这里有几个问题。

首先，您似乎认为 ulong 在 C# 中是 32 位的，但事实并非如此。它是 64 位，所以你的结构完全映射错误。

其次，我确定您需要先设置结构 Size 成员，然后再将其传递给调用。

第三，ptcDeviceName 成员是指向宽字符串的指针。这意味着在结构本身中它是 4 个字节。我可能会将其设为IntPtr。然后，您需要单独分配字符串，固定它，并将指向它的指针放入该成员槽中。由于 CF 中不存在`StringToHGlobal，它看起来像这样：

public struct __NIC_STAT
{
    public uint Size;
    public IntPtr ptcDeviceName;
    public uint DeviceState;
    public uint DeviceState;
    public uint MediaType;
    public uint MediaState;
    public uint PhysicalMediaType;
    public uint LinkSpeed;
    public ulong PacketsSent;
    public ulong PacketsReceived;
    public uint InitTime;
    public uint ConnectTime;
    public ulong BytesSent;
    public ulong BytesReceived;
    public ulong DirectedBytesReceived;
    public ulong DirectedPacketsReceived;
    public uint PacketsReceiveErrors;
    public uint PacketsSendErrors;
    public uint ResetCount;
    public uint MediaSenseConnectCount;
    public uint MediaSenseDisconnectCount;
};

....
var myStruct = new __NIC_STAT();
myStruct.Size = (15 * 4) + (6 * 8);
var name = "PCI\\Manixx1\0";
var nameBytes = Encoding.Unicode.GetBytes(name);
myStruct.ptcDeviceName = Marshal.AllocHGlobal(nameBytes.Length);
try
{
    Marshal.Copy(nameBytes, 0, myStruct.ptcDeviceName, nameBytes.Length);
    // make the IOCTL call, a-la
    NativeMethods.DeviceIoControl(...., ref myStruct, ....);
}
finally
{
    Marshal.FreeHGlobal(myStruct.ptcDeviceName);
}