private static void TransferCompletionToTask <T>(System.Threading.Tasks.TaskCompletionSource <T> tcs, System.ComponentModel.AsyncCompletedEventArgs e, Func <T> getResult, Action unregisterHandler) { if (e.UserState != tcs) { return; } try { unregisterHandler(); } finally { if (e.Cancelled) { tcs.TrySetCanceled(); } else if (e.Error != null) { tcs.TrySetException(e.Error); } else { tcs.TrySetResult(getResult()); } } }