将调度程序设置为优先队列工作

Question

我想创建一个具有Dispatcher的线程，然后从另一个线程使用该dispatcher对具有不同优先级的工作进行排队。即

var dispatcher = GetNewThreadDispatcher();
dispatcher.BeginInvoke(longRunningTask1, DispatcherPriority.Normal);
dispatcher.BeginInvoke(longRunningTask2, DispatcherPriority.Background);
dispatcher.BeginInvoke(longRunningTask3, DispatcherPriority.Normal);

在本例中，后台线程将执行longRunningTask1，然后执行longRunningTask2、longRunningTask3。我在创建干净的GetNewThreadDispatcher()时遇到了困难，有什么帮助吗？

Answer 1

您可以尝试创建新的后台线程( http://msdn.microsoft.com/en-us/library/7a2f3ay4(v=vs.90).aspx并为其获取Dispatcher：

Dispatcher dispatcher = Dispatcher.FromThread(workerThread);

一些编辑:你需要执行

OnThreadStart中的Dispatcher dispatcher=Dispatcher.CurrentDispatcher或Dispatcher.Run。但有趣的是:在执行之后

workerThread.Start();
Dispatcher dispatcher = Dispatcher.FromThread(workerThread);  

dispatcher为null，但在执行之后

workerThread.Start();
Console.WriteLine("main thread: Starting worker thread...");
Dispatcher dispatcher = Dispatcher.FromThread(workerThread); 

dispatcher正在填充

添加：

    static void OnThreadStart()
    {
       Dispatcher.Run();
    }


    private Dispatcher GetNewThreadDispatcher()
    {
        Thread workerThread=null;
        try
        {
           workerThread = new Thread(OnThreadStart);
           workerThread.IsBackground = true;
           workerThread.Start();
           int waitingCiclesCount = 100;
           int cicleIndex = 0;
           int sleepTimeInMiliseconds = 100;
           Dispatcher dispatcher = null;
           while (cicleIndex < waitingCiclesCount)
           {
               dispatcher = Dispatcher.FromThread(workerThread);
               if (dispatcher!=null)
                   break;
               Thread.Sleep(sleepTimeInMiliseconds);
               cicleIndex = cicleIndex + 1;

           }
           if (dispatcher==null)
           {
               workerThread.Abort();
               return null;
           }
           Console.WriteLine(String.Format("thread with id={0} started", workerThread.ManagedThreadId));
           return dispatcher;
        }
        catch (Exception)
        {
            if (workerThread!=null)
                workerThread.Abort();
            return null;
        }
    }

    public MainWindow()
    {
        InitializeComponent();

        TestWorker worker=new TestWorker();
        Dispatcher dispatcher1 = GetNewThreadDispatcher();
        if(dispatcher1!=null)
            dispatcher1.BeginInvoke(new TestDelegate(worker.DoWork1), DispatcherPriority.Normal);
        else
        {
            MessageBox.Show("Cant create dispatcher1");
        }
        Dispatcher dispatcher2 = GetNewThreadDispatcher();
        if (dispatcher2!=null)
            dispatcher2.BeginInvoke(new TestDelegate(worker.DoWork2), DispatcherPriority.Normal);
        else
        {
            MessageBox.Show("Cant create dispatcher2");
        }
    }   

这段代码在我的测试wpf应用程序中工作，但我不是多线程专家。也许有人会纠正我，或者在回复中添加一些信息。