WriteableBitmap的在后台工作

Question

我现在有一个循环是这样的：

foreach(var item in theList) 
{ 
//create writeablebitmap from item.GetPicture() which returns a stream. 
//do stuff with it 
//save it to isolated storage 
} 

这是一个非常长期运行的进程，因为有吨图像。我试图把它放在后台工作，但你不能在那里创建WriteableBitmaps（他们必须在UI线程上）。问题在于界面完全没有反应。

我该如何让它在每个循环中处理一次按键/ UI，以确保它能够响应用户的操作？

Answer 1

BackgroundWorker backgroundWorker = new BackgroundWorker(); 
backgroundWorker.DoWork += (s, e) => 
{ 
    foreach(var item in theList) 
    { 
     var item _ = item; 
     Deployment.Dispatcher.BeginInvoke(() => 
     { 
      // do your stuff on UI thread with item_ 
     }); 
     Thread.Sleep(milliseconds); //experiment with delay to find balance between UI responsiveness and performance 
    } 
}; 
backgroundWorker.RunWorkAsync();