TaskScheduler

两种TaskScheduler

• ThreadPoolTaskScheduler（默认，线程池调度形式）
• SychronizationTaskScheduler

 

Task t = new Task(() =>
            {
                try
                {
                    //耗时操作
                    Thread.Sleep(4000);
                    this.label1.Text = "hello";
                }
                catch (Exception ex)
                {
                    throw;
                }
            });

            t.Start(TaskScheduler.FromCurrentSynchronizationContext());

以上方法会阻塞主线程，造成主界面卡顿，改进后如下：

耗时操作放在线程池中，更新结果放在同步上下文中

private void button1_Click(object sender, EventArgs e)
        {
            Task t = Task.Run(() =>
            {
                try
                {
                    //耗时操作
                    Thread.Sleep(4000);
                }
                catch (Exception ex)
                {
                    throw;
                }
            }).ContinueWith(ta =>
            {
                //更新操作
                this.label1.Text = "hello";
            }, TaskScheduler.FromCurrentSynchronizationContext());
        }

 

自定义scheduler

 public class PerThreadScheduler : TaskScheduler
    {
        protected override IEnumerable<Task> GetScheduledTasks()
        {
            throw new NotImplementedException();
        }

        protected override void QueueTask(Task task)
        {
            Thread t = new Thread(() =>
            {
                TryExecuteTask(task);
            });

            t.Start();
        }

        protected override bool TryExecuteTaskInline(Task task, bool taskWasPreviouslyQueued)
        {
            throw new NotImplementedException();
        }
    }

 Task 、TaskScheduler 、Thread 、ThreadPoll关系图