小编Dan*_*ant的帖子

以下是一些显示意外行为的简单代码:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        _UI = TaskScheduler.FromCurrentSynchronizationContext();
        Loaded += new RoutedEventHandler(MainWindow_Loaded);
    }

    TaskScheduler _UI;

    void MainWindow_Loaded(object sender, RoutedEventArgs e)
    {
        Task.Factory.StartNew(() =>
        {
            //Expected: Worker thread
            //Found: Worker thread
            DoSomething();
        })
        .ContinueWith(t =>
            {
                //Expected: Main thread
                //Found: Main thread
                DoSomething();

                Task.Factory.StartNew(() =>
                {
                    //Expected: Worker thread
                    //Found: Main thread!!!
                    DoSomething();
                });
            }, _UI);
    }

    void DoSomething()
    {
        Debug.WriteLine(Thread.CurrentThread.ManagedThreadId.ToString());
    }
}

为什么内部任务在主线程中执行？我该如何防止这种行为？