使用TaskScheduler 调度器 实现跨线程的控件访问

         //任务调度器
         TaskScheduler UIscheduler = null;
         public Form1()
         {
             //获取任务调度器
             UIscheduler = TaskScheduler.FromCurrentSynchronizationContext();
             InitializeComponent();
         }

         private void btnTaskScheduler_Click(object sender, EventArgs e)
         {
             System.Threading.CancellationTokenSource cts = new System.Threading.CancellationTokenSource();
             //启动一个任务线程
             Task<int> t = Task.Run(() =>Sum());
             //使用UIscheduler 调度器 实现跨线程的控件访问
             t.ContinueWith(task => txtRes.Text = t.Result.ToString(), cts.Token,TaskContinuationOptions.OnlyOnRanToCompletion,UIscheduler);
             t.ContinueWith(task => txtRes.Text = "Error",System.Threading.CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted,UIscheduler);
         }
         private int Sum(int num)
         {
             int res = ;
             for (int i = ; i <= num; i++)
             {
                 checked { res += i; }
                 //res += i;
             }
             return res;
         }