public static unsafe void EnumerateDeviceInterfaces <TContext> (
DeviceInfoListHandle devs, ref SP_DEVINFO_DATA devInfo,
ref Guid interfaceGuid, EnumerateDeviceInterfacesFunc <TContext> callback,
TContext context
) where TContext : class
{
try {
var deviceInterfaceData = new SP_DEVICE_INTERFACE_DATA();
deviceInterfaceData.cbSize = (uint)Marshal.SizeOf(deviceInterfaceData.GetType());
for (
UInt32 memberIndex = 0;
SetupDiEnumDeviceInterfaces(
devs.DangerousGetHandle(), ref devInfo,
ref interfaceGuid, memberIndex,
ref deviceInterfaceData
);
memberIndex++
)
{
uint requiredSize;
// We can't use a struct for this because the CLR's interpretation of
// alignment is different from Win32's on x64 :(
var buffer = new byte[1024 + 4];
fixed(byte *pBuffer = buffer)
{
// Account for differences in alignment strategy
if (Environment.Is64BitProcess)
{
*(UInt32 *)pBuffer = 8;
}
else
{
*(UInt32 *)pBuffer = (uint)(4 + Marshal.SystemDefaultCharSize);
}
SetupDiGetDeviceInterfaceDetail(
devs.DangerousGetHandle(), ref deviceInterfaceData,
new IntPtr(pBuffer), (UInt32)buffer.Length,
out requiredSize, ref devInfo
);
var lastError = Marshal.GetLastWin32Error();
if (lastError != 0)
{
throw new Win32Exception(lastError);
}
var devicePath = new String(
(char *)(pBuffer + 4)
);
callback(
devs, ref devInfo,
ref deviceInterfaceData, devicePath,
context
);
}
}
{
var lastError = Marshal.GetLastWin32Error();
if ((lastError != 0) && (lastError != ERROR_NO_MORE_ITEMS))
{
throw new Win32Exception(lastError);
}
}
} finally {
}
}
