public static T QueryInterface <T>(IUnknown obj) where T : class, IUnknown
{
if (!(obj is T))
{
var guid = InterfaceRuntimeInfo <T> .ComGuid;
var ptr = obj.QueryNativeInterface(ref guid);
return(InterfaceRuntimeInfo <T> .CreateRcw(ptr, true));
}
return((T)obj);
}
public static T QueryInterfaceOrNull <T>(IUnknown obj) where T : class, IUnknown
{
var casted = obj as T;
if (casted == null)
{
const int E_NOINTERFACE = unchecked ((int)0x80004002);
try {
var guid = InterfaceRuntimeInfo <T> .ComGuid;
var ptr = obj.QueryNativeInterface(ref guid);
return(InterfaceRuntimeInfo <T> .CreateRcw(ptr, true));
} catch (COMException ex) when(ex.HResult == E_NOINTERFACE)
{
return(null);
}
}
return(casted);
}
