internal static extern unsafe bool SetupDiEnumDeviceInterfaces(
DeviceInformationSetHandle DeviceInfoSet,
IntPtr DeviceInfoData,
ref Guid InterfaceClassGuid,
UInt32 MemberIndex,
ref DeviceInterface.Native DeviceInterfaceData
);
internal static extern unsafe bool SetupDiGetDeviceInterfaceDetailW(
DeviceInformationSetHandle DeviceInfoSet,
ref DeviceInterface.Native DeviceInterfaceData,
byte *DeviceInterfaceDetailData,
UInt32 DeviceInterfaceDetailDataSize,
ref UInt32 RequiredSize,
IntPtr DeviceInfoData
);
private unsafe bool TryGetInterface(uint interfaceIndex, out DeviceInterface?ret)
{
DeviceInterface.Native native = new DeviceInterface.Native();
native.cdSize = (uint)Marshal.SizeOf(typeof(DeviceInterface.Native));
try {
bool success = SetupDiEnumDeviceInterfaces(
handle,
IntPtr.Zero,
ref guid,
interfaceIndex,
ref native
);
if (!success)
{
throw new Win32Exception();
}
} catch (Win32Exception err) when(err.NativeErrorCode == ERROR_NO_MORE_ITEMS)
{
ret = null;
return(false);
}
{
bool success;
UInt32 requiredSize = 0;
try {
success = SetupDiGetDeviceInterfaceDetailW(
handle,
ref native,
null,
0,
ref requiredSize,
IntPtr.Zero
);
if (!success)
{
throw new Win32Exception();
}
} catch (Win32Exception err) when(err.NativeErrorCode == ERROR_INSUFFICIENT_BUFFER)
{
}
byte[] buffer = new byte[requiredSize];
int varPartOffset = (int)Marshal.OffsetOf(typeof(DeviceInterface.DetailsNative), "data");
int structSize = Marshal.SizeOf(typeof(DeviceInterface.DetailsNative));
fixed(byte *bufferP = buffer)
{
*(UInt32 *)bufferP = (uint)structSize;
success = SetupDiGetDeviceInterfaceDetailW(
handle,
ref native,
bufferP,
requiredSize,
ref requiredSize,
IntPtr.Zero
);
if (!success)
{
throw new Win32Exception();
}
char * stringPtr = (char *)(bufferP + varPartOffset);
string filePath = new string(stringPtr);
ret = native.AsManaged(filePath);
return(true);
}
}
}
