C#使用WebClient时，如果状态码不为200时，如何获取请求返回的内容

Bertha 。 2023-06-24 08:22 46阅读 0赞

### 文章目录 ###

*   *   *  一、事故现场
         *  二、解决方法

--------------------

### 一、事故现场 ###

使用WebClient发送请求，如果返回的状态码不是2xx或3xx，那么默认情况下会抛出异常，  
那如何才能获取到请求返回的内容呢？

### 二、解决方法 ###

可以通过try catch获取到WebException类型的异常；

*  api接口：

[HttpGet("test")]
       public ActionResult test()
       { 
           Response.StatusCode = 401;
           return Content("test");
       }

*  使用WebClient发送请求：  
    方式一：直接捕获WebException 类型异常；

public static string WebClientGetRequest(string url)
       { 
           try
           { 
               using (WebClient client = new WebClient())
               { 
                   //设置编码格式
                   client.Encoding = System.Text.Encoding.UTF8;
                   //获取数据
                   var result = client.DownloadString(url);
                   return result;
               }
           }
           catch (WebException ex)
           { 
               using (HttpWebResponse hr = (HttpWebResponse)ex.Response)
               { 
                   int statusCode = (int)hr.StatusCode;
                   StringBuilder sb = new StringBuilder();
                   StreamReader sr = new StreamReader(hr.GetResponseStream(), Encoding.UTF8);
                   sb.Append(sr.ReadToEnd());
                   Console.WriteLine("StatusCode:{0},Content:{1}", statusCode, sb);// StatusCode:401,Content:test
               }
               return "";
           }
       }

方法二：捕获 Exception 异常，然后再判断异常类型；

public static string WebClientGetRequest(string url)
       { 
           try
           { 
               using (WebClient client = new WebClient())
               { 
                   //设置编码格式
                   client.Encoding = System.Text.Encoding.UTF8;
                   //获取数据
                   var result = client.DownloadString(url);
                   return result;
               }
           }
           catch (Exception ex)
           { 
               if (ex.GetType().Name == "WebException")
               { 
                   WebException we = (WebException)ex;
                   using (HttpWebResponse hr = (HttpWebResponse)we.Response)
                   { 
                       int statusCode = (int)hr.StatusCode;
                       StringBuilder sb = new StringBuilder();
                       StreamReader sr = new StreamReader(hr.GetResponseStream(), Encoding.UTF8);
                       sb.Append(sr.ReadToEnd());
                       Console.WriteLine("StatusCode:{0},Content:{1}", statusCode, sb);// StatusCode:401,Content:test
                   }
               }
               return "";
           }
       }

--------------------