Question

我想用Dispatcher创建一个线程，然后从另一个线程使用该调度程序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);

在这种情况下，后台线程将执行longRunningTask1，然后longRunningTask2，longRunningTask3。我在创建一个干净的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主题（http://msdn.microsoft.com/en-us/library/7a2f3ay4(v=vs.90).aspx）并获取Dispatcher：

Dispatcher dispatcher = Dispatcher.FromThread(workerThread);

一些编辑：你需要执行
Dispatcher dispatcher=Dispatcher.CurrentDispatcher内的Dispatcher.Run或OnThreadStart。但有趣的是：执行后

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

dispatcher为null，但执行后

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

dispatcher正在填写

加入：

    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");
        }
    }

此代码在我的测试wpf应用程序中工作，但我不是多线程专家。可能有人会纠正我或在此回复中添加一些信息。

将Dispatcher设置为优先级队列工作

1 个答案: