使用HttpWebRequest出错时获取详细的错误信息:

try    {     //HttpWebRequest 相关代码    }     catch(WebException ex)    {         HttpWebResponse res = ex.Response as HttpWebResponse;      string strError="";       if (res.StatusCode == HttpStatusCode.InternalServerError)       {         Stream s = res.GetResponseStream();         StreamReader objReader = new StreamReader(s, System.Text.Encoding.UTF8);         strError = objReader.ReadToEnd();         objReader.Close();       }       else       {         strError = ex.Message;       }    //打印strError    }