编组结构，嵌入指针从C＃到非托管驱动程序(Marshalling struct with embedded pointer from C# to unmanaged driver)

 我正在尝试使用P / Invoked DeviceIoControl（）调用将C＃（.NET Compact Framework 3.5）与Windows CE 6 R2流驱动程序连接。 对于其中一个IOCTL代码，驱动程序需要一个DeviceIoControl输入缓冲区，该缓冲区是包含嵌入指针的以下非托管结构： 
 
typedef struct {
    DWORD address;
    const void* pBuffer;
    DWORD size; // buffer size
} IOCTL_TWL_WRITEREGS_IN;
 
 我在C＃中定义了结构： 
 
[StructLayout(LayoutKind.Sequential)]
public struct IoctlWriteRegsIn
{
    public uint Address;
    public byte[] Buffer;
    public uint Size;
}
 
 和我的P / Invoke签名为： 
 
[DllImport("coredll.dll", CharSet = CharSet.Unicode, SetLastError = true)]
static extern bool DeviceIoControl(IntPtr hDevice,
                                    UInt32 dwIoControlCode,
                                    ref IoctlWriteRegsIn lpInBuffer,
                                    UInt32 nInBufferSize,
                                    UInt32[] lpOutBuffer,
                                    UInt32 nOutBufferSize,
                                    ref UInt32 lpBytesReturned,
                                    IntPtr lpOverlapped);
 
 但是，每当我在C＃中调用DeviceIoControl（）时，它总是返回false，最后一次Win32错误为ERROR_INVALID_PARAMETER 。 这是驱动程序中IOCTL switch语句的源代码片段，它处理IOCTL代码并对输入缓冲区进行错误检查，其中inSize是nInBufferSize参数： 
 
    case IOCTL_TWL_WRITEREGS:
        if ((pInBuffer == NULL) || 
            (inSize < sizeof(IOCTL_TWL_WRITEREGS_IN)))
            {
            SetLastError(ERROR_INVALID_PARAMETER);
            break;
            }
        address = ((IOCTL_TWL_WRITEREGS_IN*)pInBuffer)->address;
        pBuffer = ((IOCTL_TWL_WRITEREGS_IN*)pInBuffer)->pBuffer;
        size = ((IOCTL_TWL_WRITEREGS_IN*)pInBuffer)->size;
        if (inSize < (sizeof(IOCTL_TWL_WRITEREGS_IN) + size))
            {
            SetLastError(ERROR_INVALID_PARAMETER);
            break;
            }
        rc = TWL_WriteRegs(context, address, pBuffer, size);
 
 我试过硬编码大小应该通过驱动程序的错误检查没有成功，这表明它是一个编组问题。 我可能没有正确定义C＃struct中的嵌入指针或者我的P / Invoke签名错误。 有任何想法吗？ 
 
 提前谢谢，本 
 
 作为参考，我可以用C ++与驱动程序通信，没有这样的问题： 
 
IOCTL_TWL_WRITEREGS_IN reg;
reg.address = 0x004B0014;
unsigned char data = 0xBE;
reg.pBuffer = &data;
reg.size = sizeof(char);

BOOL writeSuccess = DeviceIoControl(driver, IOCTL_TWL_WRITEREGS, &reg, sizeof(IOCTL_TWL_WRITEREGS_IN) + 1, NULL, 0, NULL, NULL);
 
 更新：这是有效的！ 使用JaredPar的IntPtr建议并通过SwDevMan81的建议清理我的P / Invoke签名： 
 
    [StructLayout(LayoutKind.Sequential)]
    public struct IoctlWriteRegsIn
    {
        public uint Address;
        public IntPtr Buffer;
        public uint Size;
    }

    // elided

    byte regData = 0xFF;
    GCHandle pin = GCHandle.Alloc(regData, GCHandleType.Pinned);
    IoctlWriteRegsIn writeInBuffer = new IoctlWriteRegsIn{Address = twlBackupRegA, Buffer = pin.AddrOfPinnedObject(), Size = 1};
    bool writeSuccess = DeviceIoControl(driverHandle, IoctlTwlWriteRegs, ref writeInBuffer, (uint) Marshal.SizeOf(writeInBuffer) + 1, IntPtr.Zero, 0, ref numBytesReturned, IntPtr.Zero);

    // P/Invoke signature
    [DllImport("coredll.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    static extern bool DeviceIoControl(IntPtr hDevice,
                                        UInt32 dwIoControlCode,
                                        ref IoctlWriteRegsIn lpInBuffer,
                                        UInt32 nInBufferSize,
                                        IntPtr lpOutBuffer,
                                        UInt32 nOutBufferSize,
                                        ref UInt32 lpBytesReturned,
                                        IntPtr lpOverlapped);

I'm trying to interface C# (.NET Compact Framework 3.5) with a Windows CE 6 R2 stream driver using P/Invoked DeviceIoControl() calls . For one of the IOCTL codes, the driver requires a DeviceIoControl input buffer that is the following unmanaged struct that contains an embedded pointer:
 
typedef struct {
    DWORD address;
    const void* pBuffer;
    DWORD size; // buffer size
} IOCTL_TWL_WRITEREGS_IN;
 
I defined the struct in C# as:
 
[StructLayout(LayoutKind.Sequential)]
public struct IoctlWriteRegsIn
{
    public uint Address;
    public byte[] Buffer;
    public uint Size;
}
 
and my P/Invoke signature as:
 
[DllImport("coredll.dll", CharSet = CharSet.Unicode, SetLastError = true)]
static extern bool DeviceIoControl(IntPtr hDevice,
                                    UInt32 dwIoControlCode,
                                    ref IoctlWriteRegsIn lpInBuffer,
                                    UInt32 nInBufferSize,
                                    UInt32[] lpOutBuffer,
                                    UInt32 nOutBufferSize,
                                    ref UInt32 lpBytesReturned,
                                    IntPtr lpOverlapped);
 
However, whenever I call DeviceIoControl() in C#, it always returns false, with a last Win32 error of ERROR_INVALID_PARAMETER. Here's a source code snippet from the IOCTL switch statement in the driver that handles the IOCTL code and does error checking on the input buffer, where inSize is the nInBufferSize parameter:
 
    case IOCTL_TWL_WRITEREGS:
        if ((pInBuffer == NULL) || 
            (inSize < sizeof(IOCTL_TWL_WRITEREGS_IN)))
            {
            SetLastError(ERROR_INVALID_PARAMETER);
            break;
            }
        address = ((IOCTL_TWL_WRITEREGS_IN*)pInBuffer)->address;
        pBuffer = ((IOCTL_TWL_WRITEREGS_IN*)pInBuffer)->pBuffer;
        size = ((IOCTL_TWL_WRITEREGS_IN*)pInBuffer)->size;
        if (inSize < (sizeof(IOCTL_TWL_WRITEREGS_IN) + size))
            {
            SetLastError(ERROR_INVALID_PARAMETER);
            break;
            }
        rc = TWL_WriteRegs(context, address, pBuffer, size);
 
I tried hard coding sizes that should pass the driver's error checking with no success, suggesting that it's a marshalling problem. I probably did not define the embedded pointer in the C# struct correctly or have my P/Invoke signature wrong. Any ideas?
 
Thanks in advance, Ben
 
For reference, I can talk to the driver from C++ with no problems like this:
 
IOCTL_TWL_WRITEREGS_IN reg;
reg.address = 0x004B0014;
unsigned char data = 0xBE;
reg.pBuffer = &data;
reg.size = sizeof(char);

BOOL writeSuccess = DeviceIoControl(driver, IOCTL_TWL_WRITEREGS, &reg, sizeof(IOCTL_TWL_WRITEREGS_IN) + 1, NULL, 0, NULL, NULL);
 
Update: here's what worked! Used JaredPar's IntPtr suggestion and cleaned up my P/Invoke signature by SwDevMan81's suggestion:
 
    [StructLayout(LayoutKind.Sequential)]
    public struct IoctlWriteRegsIn
    {
        public uint Address;
        public IntPtr Buffer;
        public uint Size;
    }

    // elided

    byte regData = 0xFF;
    GCHandle pin = GCHandle.Alloc(regData, GCHandleType.Pinned);
    IoctlWriteRegsIn writeInBuffer = new IoctlWriteRegsIn{Address = twlBackupRegA, Buffer = pin.AddrOfPinnedObject(), Size = 1};
    bool writeSuccess = DeviceIoControl(driverHandle, IoctlTwlWriteRegs, ref writeInBuffer, (uint) Marshal.SizeOf(writeInBuffer) + 1, IntPtr.Zero, 0, ref numBytesReturned, IntPtr.Zero);

    // P/Invoke signature
    [DllImport("coredll.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    static extern bool DeviceIoControl(IntPtr hDevice,
                                        UInt32 dwIoControlCode,
                                        ref IoctlWriteRegsIn lpInBuffer,
                                        UInt32 nInBufferSize,
                                        IntPtr lpOutBuffer,
                                        UInt32 nOutBufferSize,
                                        ref UInt32 lpBytesReturned,
                                        IntPtr lpOverlapped);

原文：https://stackoverflow.com/questions/1681517