protected unsafe string GetString(IntPtr guid, int objectCode)
{
var prop = new PropertyString();
var propNative = new PropertyString.__Native();
InitHeader <PropertyString.__Native>(ref propNative.Header);
propNative.Header.Obj = objectCode;
Device.GetProperty(guid, new IntPtr(&propNative));
prop.__MarshalFrom(ref propNative);
return(prop.Text);
}