WriteableBitmap的在後臺工作

Question

我現在有一個循環是這樣的：

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

這是一個非常長期運行的進程，因爲有噸圖像。我試圖把它放在後臺工作，但你不能在那裏創建WriteableBitmaps（他們必須在UI線程上）。問題在於界面完全沒有反應。

我該如何讓它在每個循環中處理一次按鍵/ UI，以確保它能夠響應用戶的操作？

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();