SecurityException和Silverlight Web服务

Question

我一直在关注这个Silverlight tutorial，使用Twitter而不是Digg。一切工作正常，直到我尝试从服务中获取数据。

private const string TWITTER_API_URL_FORMAT = "http://api.twitter.com/1/statuses/user_timeline.xml?screen_name={0}"; 
    private void Button_Click(object sender, RoutedEventArgs e) 
    { 
     string username = searchBox.Text; 
     string url = String.Format(TWITTER_API_URL_FORMAT, username); 
     WebClient twitterService = new WebClient(); 
     twitterService.DownloadStringCompleted += new DownloadStringCompletedEventHandler(twitterService_DownloadStringCompleted); 

     label.Text = "Loading... " + url; 
     twitterService.DownloadStringAsync(new Uri(url)); 
    } 

    void twitterService_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e) 
    { 
     if (e.Error != null) 
     { 
      label.Text = String.Format("Error: {0}", e.Error); 
      return; 
     } 

     // ... 
    } 

它失败，出现以下错误：

[System.Security.SecurityException] = {System.Security.SecurityException ---> System.Security.SecurityException: Security error. 
    at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult) 
    at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.<E... 

我不知道为什么会这样。该URL是合法的。我有一个wp7 Silverlight项目，使用这个相同的代码，它工作正常。我可能做错了什么？

Answer 1

您可能会遇到跨站点脚本（XSS）错误。看看这里：Making a Service Available Across Domain Boundaries