當用戶在GWTUpload中刪除上傳的圖像時，何處調用Action？

Question

我使用GWTUpload，庫是在這裏https://code.google.com/p/gwtupload/

示例代碼在該網站上找到客戶端具有這種結構：

// Attach an image to the pictures viewer 
private OnLoadPreloadedImageHandler showImage = new OnLoadPreloadedImageHandler() { 
    public void onLoad(PreloadedImage image) { 
     //showImageFlowPanel code solution 1 
     image.setWidth("75px"); 
     showImageFlowPanel.add(image); 
    } 
}; 


private IUploader.OnFinishUploaderHandler onFinishUploaderHandler = new IUploader.OnFinishUploaderHandler() { 
     public void onFinish(IUploader uploader) { 
     if (uploader.getStatus() == Status.SUCCESS) { 

      new PreloadedImage(uploader.fileUrl(), showImage); 

      UploadedInfo info = uploader.getServerInfo(); 

      String headShotImageUrl="http://"+Window.Location.getHost()+"/" +"images/uploaded/"+info.message; 
      //headShotImage code solution 2 
      if(!"".equals(headShotImageUrl) && UriUtils.isSafeUri(headShotImageUrl)){ 
       headShotImage.setUrl(UriUtils.fromString(headShotImageUrl)); 
      } 



     } 
     } 
    }; 

的例子使用showImageFlowPanel（溶液1），用於存儲所述圖像但我想在headShotImage裏面存儲圖片，在用戶上傳圖片成功之後接收這個url，請參閱上面的headShotImage（解決方案2）代碼。

好吧，headShotImage代碼工作正常，但我不知道如何刪除它時，用戶刪除圖像。如果我在解決方案1中使用showImageFlowPanel，那麼程序會自動爲我移除圖像，而且我不需要執行任何操作。

所以我的問題是「當調用一個動作，當用戶刪除在GWTUpload上傳圖片？」

Answer 1

你必須使用setOnCancelUploaderHandler。看看這個代碼從演示中獲取。

// When the user clicks a cancel button we get an event 
uploader.addOnCancelUploadHandler ( 
    new IUploader.OnCancelUploaderHandler() { 
    public void onCancel(IUploader uploader) { 
     for (String iname : uploader.getServerMessage().getUploadedFieldNames()) { 
     // loadedImages is an temporary table where we are adding all uploaded files 
     // indexed by field name 
     Widget w = loadedImages.get(iname); 
     if (w != null) { 
      w.removeFromParent(); 
     loadedImages.remove(uploader.getInputName()); 
     } 
    } 
    } 
});