private void ButtonSearch_Click(object sender, RoutedEventArgs e) { if (NetworkInterface.NetworkInterfaceType != NetworkInterfaceType.None) { if (BookToSearch.Text.Equals("") || BookToSearch.Text == "" || BookToSearch.Text == null) { MessageBox.Show("请输入需要搜索的书名或者关键字!"); } else { string BookTitle = BookToSearch.Text; string url = @"http://api.douban.com/v2/book/search?q=" + @BookTitle; //get book info from douban.com downDelegate = setConent; System.Net.WebRequest request = HttpWebRequest.Create(url); IAsyncResult result = (IAsyncResult)request.BeginGetResponse(ResponseCallback, request); //async web request } } else { Debug.WriteLine("[DEBUG]Network Interface Available Status:" + NetworkInterface.GetIsNetworkAvailable()); Debug.WriteLine("[DEBUG]Network Interface Type Status:" + NetworkInterface.NetworkInterfaceType); MessageBox.Show("搜索书籍信息需要网络连接,请开启手机的移动网络。"); } }