WPF跨线程更新UI的3种方法

1）Dispatcher

void ProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
      this.Dispatcher.Invoke(DispatcherPriority.Normal, new System.Windows.Forms.MethodInvoker(delegate()
      {
           this.ProgressBar.Value = e.ProgressPercentage;
      }));
}

2） DispatcherTimer

// Create a Timer with a Normal Priority

_timer = new DispatcherTimer();



// Set the Interval to 2 seconds

_timer.Interval = TimeSpan.FromMilliseconds(2000); 



// Set the callback to just show the time ticking away

// NOTE: We are using a control so this has to run on 

// the UI thread

_timer.Tick += new EventHandler(delegate(object s, EventArgs a) 

{ 

    statusText.Text = string.Format(

        "Timer Ticked:  {0}ms", Environment.TickCount); 

});



// Start the timer

_timer.Start();

3）BackgroundWorker

BackgroundWorker _backgroundWorker = new BackgroundWorker();


...


// Set up the Background Worker Events


_backgroundWorker.DoWork += _backgroundWorker_DoWork;


backgroundWorker.RunWorkerCompleted += 


    _backgroundWorker_RunWorkerCompleted;






// Run the Background Worker


_backgroundWorker.RunWorkerAsync(5000);






...






// Worker Method


void _backgroundWorker_DoWork(object sender, DoWorkEventArgs e)


{


    // Do something


}






// Completed Method


void _backgroundWorker_RunWorkerCompleted(


    object sender, 


    RunWorkerCompletedEventArgs e)


{


    if (e.Cancelled)


    {


        statusText.Text = "Cancelled";


    }


    else if (e.Error != null) 


    {


        statusText.Text = "Exception Thrown";


    }


    else 


    {


        statusText.Text = "Completed";


    }


}