WPF进度控制调度仍要堵塞UI线程 [英] WPF ProgressBar Control Dispatch still blocking UI Thread

问题描述

我使用WPF试图在更新进度条的后台运行一个线程。我不婉让我运行下面的code阻塞UI线程。然而，用户界面​​仍然受阻。它似乎很简单，我究竟做错了什么？

  Dispatcher.BeginInvoke（
        （的ThreadStart）委托（）{
            对于（双I = progressBar_ChangeProgress.Minimum;
                I＆LT; progressBar_ChangeProgress.Maximum;
                我++）
                {
                    为（中间体B = 0; b将亿; b ++）{}
                    progressBar_ChangeProgress.Value =我;
                }
            EnableAllInputControls（）;
        }，DispatcherPriority.Background）;
 

解决方案

为什么不利用的BackgroundWorker 在这种情况下...

 无效围棋（）
        {
            BackgroundWorker的工作人员=新的BackgroundWorker（）;
            worker.WorkerReportsProgress = TRUE;
            worker.ProgressChanged + =新ProgressChangedEventHandler（worker_ProgressChanged）;
            worker.DoWork + =新DoWorkEventHandler（worker_DoWork）;
            worker.RunWorkerAsync（）;
        }

        无效worker_ProgressChanged（对象发件人，ProgressChangedEventArgs E）
        {
            progressBar_ChangeProgress.Value = e.ProgressPercentage;
        }

        无效worker_DoWork（对象发件人，DoWorkEventArgs E）
        {
            BackgroundWorker的工人=发件人为BackgroundWorker的;
            为（中间体B = 0; b将100; b + +）
            {
                Thread.sleep代码（100）;
                worker.ReportProgress（B）;
            }
        }
 

更新：

如果你想使用调度;优先级设置为正常并在后台线程然后调用UI线程的方法来提供更新进行处理。

 无效围棋（）
        {
            的ThreadStart开始=委托（）
            {
                //这是发生在后台线程
                的for（int i = 0; I＆LT; 100;我++）
                {
                    //这是速度变慢;没有真正的意义
                    Thread.sleep代码（100）;

                    //这将封送我们回到UI线程
                    Dispatcher.Invoke（DispatcherPriority.Normal，
                                         新的动作＆LT; INT＆GT;（更新），我
                                         ）;
                }

            };

            新的Thread（开始）。开始（）;
        }

        无效更新（int值）
        {
            //这是发生在UI线程
            _progressBar.Value =价值;
        }
 

I am using WPF trying to run a Thread in the background that updates a progress bar. I don't wan to block the UI thread so I am running the following code. However the UI still blocked. It seems so simple, what am I doing wrong?

       Dispatcher.BeginInvoke(
        (ThreadStart) delegate(){                   
            for(double i = progressBar_ChangeProgress.Minimum;
                i < progressBar_ChangeProgress.Maximum;
                i++)
                {
                    for (int b = 0; b < 100000000; b++) { }
                    progressBar_ChangeProgress.Value = i;
                }
            EnableAllInputControls();
        }, DispatcherPriority.Background);

解决方案

Why not leverage the BackgroundWorker in this scenario...

        void Go()
        {
            BackgroundWorker worker = new BackgroundWorker();
            worker.WorkerReportsProgress = true;
            worker.ProgressChanged += new ProgressChangedEventHandler(worker_ProgressChanged);
            worker.DoWork += new DoWorkEventHandler(worker_DoWork);
            worker.RunWorkerAsync();
        }

        void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            progressBar_ChangeProgress.Value = e.ProgressPercentage;
        }

        void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker worker = sender as BackgroundWorker;
            for (int b = 0; b < 100; b++) 
            {
                Thread.Sleep(100);
                worker.ReportProgress(b);
            }
        }

UPDATE:

If you are wanting to use the Dispatcher; set the priority to Normal and perform the processing on the background thread then calling a method on the UI thread to provide the update.

        void Go()
        {
            ThreadStart start = delegate()
            {
                //this is taking place on the background thread
                for (int i = 0; i < 100; i++)
                {
                    //this is slowing things down; no real relevance
                    Thread.Sleep(100);

                    //this will marshal us back to the UI thread
                    Dispatcher.Invoke(DispatcherPriority.Normal,
                                         new Action<int>(Update), i
                                         );
                }

            };

            new Thread(start).Start();
        }

        void Update(int value)
        {
            //this is taking place on the UI thread
            _progressBar.Value = value;
        }

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