来自C+的C#USB驱动程序+；：SetupDiGetDeviceInterface详细信息

试图从C#调用SetupDiGetDeviceInterfaceDetail时遇到问题。它总是返回1784错误代码（“提供的用户缓冲区对于请求的操作无效”）。这是我的C#代码：

Classe Win32：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace USB_test
{
[StructLayout(LayoutKind.Sequential)]
public class SP_DEVINFO_DATA
{
    public uint cbSize;
    public Guid classGuid;
    public uint devInst;
    public IntPtr reserved;
};

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public class SP_DEVICE_INTERFACE_DETAIL_DATA
{
    public uint cbSize;
    public byte[] devicePath;
}

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)]
public class SP_DEVICE_INTERFACE_DATA
{
    public uint cbSize;
    public Guid InterfaceClassGuid;
    public uint Flags;
    public IntPtr Reserved;
}

public class Win32
{
    public static uint ANYSIZE_ARRAY = 1000;

    [DllImport("setupapi.dll", SetLastError = true)]
    public static extern IntPtr SetupDiGetClassDevs(ref Guid ClassGuid, IntPtr Enumerator, IntPtr hwndParent, uint Flags);   

    [DllImport("setupapi.dll", SetLastError = true)]
    public static extern Boolean SetupDiEnumDeviceInfo(IntPtr lpInfoSet, UInt32 dwIndex, SP_DEVINFO_DATA devInfoData);

    [DllImport(@"setupapi.dll", SetLastError = true, CharSet = CharSet.Auto)]
    public static extern Boolean SetupDiEnumDeviceInterfaces(IntPtr hDevInfo, IntPtr devInfo, ref Guid interfaceClassGuid, uint memberIndex, SP_DEVICE_INTERFACE_DATA deviceInterfaceData);

    [DllImport(@"setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
    public static extern Boolean SetupDiGetDeviceInterfaceDetail(IntPtr hDevInfo, SP_DEVICE_INTERFACE_DATA deviceInterfaceData, SP_DEVICE_INTERFACE_DETAIL_DATA deviceInterfaceDetailData, uint deviceInterfaceDetailDataSize, out uint requiredSize, SP_DEVINFO_DATA deviceInfoData);

    public const int DIGCF_PRESENT = 0x02;
    public const int DIGCF_DEVICEINTERFACE = 0x10;
    public const int SPDRP_DEVICEDESC = (0x00000000);
    public const long ERROR_NO_MORE_ITEMS = 259L;
    }
}

如果它能帮助某人，这就是解决方案：

IntPtr detailDataBuffer = Marshal.AllocHGlobal((int)needed);
Marshal.WriteInt32(detailDataBuffer, (IntPtr.Size == 4) ? (4 + Marshal.SystemDefaultCharSize) : 8);
uint nBytes = needed;

bool result4 = Win32.SetupDiGetDeviceInterfaceDetail(hDevInfo, ifData, detailDataBuffer, nBytes, out needed, null);
if (result4 == false)
{
    int error = Marshal.GetLastWin32Error();
    if (error != Win32.ERROR_NO_MORE_ITEMS)
        throw new Win32Exception(error);
}

IntPtr pDevicePathName = new IntPtr(detailDataBuffer.ToInt32() + 4);
String devicePathName = Marshal.PtrToStringAuto(pDevicePathName);

附加说明：如果在64位计算机上运行，或在强制64位模式下运行，则pDevicePathName指针的上行将引用64位指针，而不是32位指针

---

IntPtr pDevicePathName=newintptr（detailDataBuffer.ToInt64（）+8）

结构是一个可变大小的结构，无法自动编组。你需要自己去做

您需要删除

SP\u设备\u接口\u详细信息\u数据

类型。这对你没用。将

SetupDiGetDeviceInterfaceDetail

的声明更改为：

[DllImport(@"setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern Boolean SetupDiGetDeviceInterfaceDetail(
    IntPtr hDevInfo, 
    SP_DEVICE_INTERFACE_DATA deviceInterfaceData, 
    IntPtr deviceInterfaceDetailData, 
    uint deviceInterfaceDetailDataSize, 
    out uint requiredSize, 
    SP_DEVINFO_DATA deviceInfoData
);

在第一次调用

SetupDiGetDeviceInterfaceDetail

时传递

IntPtr.Zero

。然后通过调用

Marshal.AllocHGlobal

来分配所需大小的缓冲区。然后将大小写入该缓冲区的前4个字节。然后再次调用

SetupDiGetDeviceInterfaceDetail

大致如下：

bool result3 = Win32.SetupDiGetDeviceInterfaceDetail(hDevInfo, ifData, IntPtr.Zero, 0, 
    out needed, null);
if(!result3)
{
    int error = Marshal.GetLastWin32Error();
}
// expect that result3 is false and that error is ERROR_INSUFFICIENT_BUFFER = 122, 
// and needed is the required size

IntPtr DeviceInterfaceDetailData = Marshal.AllocHGlobal((int)needed);
try
{
    uint size = needed;
    Marshal.WriteInt32(DeviceInterfaceDetailData, (int)size);
    bool result4 = Win32.SetupDiGetDeviceInterfaceDetail(hDevInfo, ifData, 
        DeviceInterfaceDetailData, size, out needed, null);
    if(!result4)
    {
        int error = Marshal.GetLastWin32Error();
    }
    // do whatever you need with DeviceInterfaceDetailData
}
finally
{
    Marshal.FreeHGlobal(DeviceInterfaceDetailData);
}

---

对不起，完成了。感谢您的迟来，我们知道Windows的东西发生了变化，包括它们的DLL。你对此有任何更新吗？我尝试了完整的复制/粘贴，少了几个变量，但没有其他内容。即使在将第三个参数的签名更改为IntPtr后，调用3和4结果仍会失败。非常感谢David的帮助和耐心！您不想写入返回的大小。根据MSDN：cbSize成员始终包含数据结构固定部分的大小，而不是反映末尾可变长度字符串的大小。这行应该写下（IntPtr.Size==8？8:4+Marshal.SystemDefaultCharSize），最后一位非常重要！

bool result3 = Win32.SetupDiGetDeviceInterfaceDetail(hDevInfo, ifData, IntPtr.Zero, 0, 
    out needed, null);
if(!result3)
{
    int error = Marshal.GetLastWin32Error();
}
// expect that result3 is false and that error is ERROR_INSUFFICIENT_BUFFER = 122, 
// and needed is the required size

IntPtr DeviceInterfaceDetailData = Marshal.AllocHGlobal((int)needed);
try
{
    uint size = needed;
    Marshal.WriteInt32(DeviceInterfaceDetailData, (int)size);
    bool result4 = Win32.SetupDiGetDeviceInterfaceDetail(hDevInfo, ifData, 
        DeviceInterfaceDetailData, size, out needed, null);
    if(!result4)
    {
        int error = Marshal.GetLastWin32Error();
    }
    // do whatever you need with DeviceInterfaceDetailData
}
finally
{
    Marshal.FreeHGlobal(DeviceInterfaceDetailData);
}