private static IEnumerable <Guid> EnumerateClasses(CmClassType flags)
{
Guid guid = Guid.Empty;
int index = 0;
while (true)
{
var result = DeviceNativeMethods.CM_Enumerate_Classes(index++, ref guid, flags);
if (result == CrError.NO_SUCH_VALUE)
{
break;
}
if (result == CrError.INVALID_DATA)
{
continue;
}
if (result != CrError.SUCCESS)
{
throw new ArgumentException($"Failed to enumerate device class. Error: {result}");
}
yield return(guid);
}
}
internal static extern CrError CM_Enumerate_Classes(int ulClassIndex, ref Guid ClassGuid, CmClassType ulFlags);
private static NtResult <SafeHGlobalBuffer> GetClassProperty(Guid class_guid, CmClassType flags, DEVPROPKEY key, out DEVPROPTYPE type, bool throw_on_error)
{
int length = 0;
var result = DeviceNativeMethods.CM_Get_Class_PropertyW(class_guid, key, out type, SafeHGlobalBuffer.Null, ref length, flags);
if (result != CrError.BUFFER_SMALL)
{
return(result.ToNtStatus().CreateResultFromError <SafeHGlobalBuffer>(throw_on_error));
}
using (var buffer = new SafeHGlobalBuffer(length))
{
return(DeviceNativeMethods.CM_Get_Class_PropertyW(class_guid, key, out type, buffer,
ref length, flags).ToNtStatus().CreateResult(throw_on_error, () => buffer.Detach()));
}
}