Windows Phone 7 DownloadStringCompleted和什么是网址？还是params？

Question

private void button7_Click(object sender, RoutedEventArgs e) 
    { 
     WebClient client = new WebClient(); 
     client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted); 
     client.DownloadStringAsync(new Uri("http://asd.com/bb")); 
    } 

    void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e) 
    { 
     if (e.Error == null) 
     { 
      MessageBox.Show(e.Result); 

     } 
     else { 
      MessageBox.Show("err: " + e.Error.ToString()); 
     } 
    } 

我该如何从DownloadStringCompleted获取url？或者我如何将一些参数传递给我的DownloadStringCompleted？

请帮助

Answer 1

您可以通过DownloadStringAsync第二个参数传递任何对象。然后，您可以通过DownloadStringCompletedEventArgs .UserState检索该对象。

private void button7_Click(object sender, RoutedEventArgs e) 
{ 
    WebClient client = new WebClient(); 
    client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted); 
    var uri = new Uri("http://asd.com/bb"); 
    client.DownloadStringAsync(uri, uri); 
} 

void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e) 
{ 
    var uri = e.UserState as Uri; 
    //... 
}