http://bbs.csdn.net/topics/390883361
来自此处.
问题.某个接口.返回错误消息用的是400.所以必须知道具体的内容.
using System;using System.IO;using System.Net;public class Test{ static void Main() { HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://csharpindepth.com/asd"); try { using (Stream data = request.GetResponse().GetResponseStream()) { using (StreamReader reader = new StreamReader(data)) { string text = reader.ReadToEnd(); Console.WriteLine(text); } } } catch (WebException ex) { HttpWebResponse response = (HttpWebResponse) ex.Response; Console.WriteLine("Error code: {0}", response.StatusCode); if (response.StatusCode == HttpStatusCode.BadRequest) { using (Stream data = response.GetResponseStream()) { using (StreamReader reader = new StreamReader(data)) { string text = reader.ReadToEnd(); Console.WriteLine(text); } } } } }}原文：http://www.cnblogs.com/forhell/p/6655351.html