当我们遇到一些异步执行又无法等待时的逻辑，比如动画的执行。
而业务上又需要等待逻辑的完成，再去处理后续的操作。这时需要转成异步方法
如下，同步执行一个动画后，再输出日志：
1 private async void TaskCompleteSourceAwait_OnClick(object sender, RoutedEventArgs e) 2 { 3 bool isCompleted = await AwaitByTaskCompletionAsync(new Storyboard() { Duration = new Duration(TimeSpan.FromSeconds(2)) }); 4 Debug.WriteLine($"TaskCompleteSourceAwait_OnClick end:{isCompleted}"); 5 }
通过TaskCompletionSource如何转化为异步方法，并等待动画完成？
1 /// <summary> 2 /// 执行动画 3 /// </summary> 4 /// <param name="storyboard"></param> 5 /// <returns></returns> 6 public static async Task<bool> AwaitByTaskCompletionAsync(Storyboard storyboard) 7 { 8 var taskCompletionSource = new TaskCompletionSource<bool>(); 9 10 Debug.WriteLine("Storyboard start"); 11 12 storyboard.Completed += OnStoryboardCompleted; 13 storyboard.Begin(); 14 15 void OnStoryboardCompleted(object sender, EventArgs e) 16 { 17 Debug.WriteLine("Storyboard end"); 18 storyboard.Completed -= OnStoryboardCompleted; 19 taskCompletionSource.SetResult(true); 20 } 21 return await taskCompletionSource.Task; 22 }
测试效果：
参考资料：