引發WebException被逮住

Question

我有以下代碼：

try 
{ 
    using (var myHttpWebResponse = (HttpWebResponse) httPrequestCreated.GetResponse()) 
    { 
     var streamResponse = myHttpWebResponse.GetResponseStream(); 

     if (streamResponse != null) 
     { 
      var streamRead = new StreamReader(streamResponse); 
      var readBuff = new Char[256]; 
      var count = streamRead.Read(readBuff, 0, 256);   

      while (count > 0) 
      { 
       var outputData = new String(readBuff, 0, count); 
       finalResopnse += outputData; 
       count = streamRead.Read(readBuff, 0, 256); 
      } 
      streamRead.Close(); 
      streamResponse.Close(); 
      myHttpWebResponse.Close(); 

     } 
    } 
} 
catch (WebException ex) 
{ 
    MessageBox.Show("something went wrong"); 
} 

錯誤代碼是404 Not Found，但不是一個消息，我得到了以下錯誤：

爲什麼例外從未被抓住？

Answer 1

你可能有一次機會異常在Visual Studio再追開啓。

嘗試在沒有調試器的情況下運行應用程序（Ctrl + F5）。或者，如果你得到這個對話框，你可以按Run（F5）來獲得你的消息框。

Answer 2

你確定你'捕捉'相同類型的異常嗎？相反WebException抓的只是Exception，看看你是否得到MessageBox

try 
    { 
     using (var myHttpWebResponse = (HttpWebResponse) httPrequestCreated.GetResponse()) 
     { 
      var streamResponse = myHttpWebResponse.GetResponseStream(); 

      if (streamResponse != null) 
      { 
       var streamRead = new StreamReader(streamResponse); 
       var readBuff = new Char[256]; 
       var count = streamRead.Read(readBuff, 0, 256);   

       while (count > 0) 
       { 
        var outputData = new String(readBuff, 0, count); 
        finalResopnse += outputData; 
        count = streamRead.Read(readBuff, 0, 256); 
       } 
       streamRead.Close(); 
       streamResponse.Close(); 
       myHttpWebResponse.Close(); 

      } 
     } 

    } 
    catch (Exception ex) 
    { 
     MessageBox.Show(string.format("this went wrong: {0}", ex.Message)); 
    } 

編輯：看着你的PIC緊密我覺得你以前見過的異常​​被拋出你的catch塊。在您VS按Ctrl + Alt + E鍵，並確保Throw檢查Common Language Runtime Exceptions是選中