c# 异步更新UI 不阻塞  流畅

Task task = Task.Factory.StartNew(() =>
{

    DoLongRunningWork(); // 耗时运算
});
Task UITask= task.ContinueWith(() =>

    {

     this.TextBlock1.Text = "Complete"; //运算后 赋值

    }, TaskScheduler.FromCurrentSynchronizationContext());

btnStop.Invoke(new Action(delegate() { this.btnStop.Enabled = false; }));

btnStart.Invoke(new Action(delegate() { this.btnStart.Enabled = true; }));