httpWebRequest请求错误,基础连接已经关闭: 连接被意外关闭

Posted 2020-09-10 幸福安康

C# 用httpWebRequest 执行post请求出现“请求错误,基础连接已经关闭: 连接被意外关闭”，解决方法：

System.Net.HttpWebRequest request;

request.ProtocolVersion = HttpVersion.Version10; 

 

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

GET方法:

 

public string DoWebRequest(string url)
        {
            HttpWebResponse webResponse = null;
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
            webRequest.Method = "POST";
            string responseStr = null;
            webRequest.Timeout = 50000;
            webRequest.ContentType = "text/html; charset=gb2312";
            try
            {
                //尝试获得要请求的URL的返回消息
                webResponse = (HttpWebResponse)webRequest.GetResponse();
            }
            catch (WebException e)
            {
                //发生网络错误时,获取错误响应信息
                responseStr = "发生网络错误！请稍后再试";
            }
            catch (Exception e)
            {
                //发生异常时把错误信息当作错误信息返回
                responseStr = "发生错误：" + e.Message;
 
            }
            finally
            {
                if (webResponse != null)
                {
                    //获得网络响应流
                    using (StreamReader responseReader = new StreamReader(webResponse.GetResponseStream(), Encoding.GetEncoding("GB2312")))
                    {
                        responseStr = responseReader.ReadToEnd();//获得返回流中的内容
                    }
                    webResponse.Close();//关闭web响应流
                }
            }
            return responseStr;
        }

 

注意：url中的中文，要先用HttpUtility.UrlEncode("内容",编码) 用服务器接收的编码，编码一下。

POST方法：

 

 private string DoWebRequestByPost(string url, string param)
        {
            HttpWebResponse webResponse = null;
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
            //使用post方式提交
            webRequest.Method = "POST";
            string responseStr = null;
            webRequest.Timeout = 50000;
            //要post的字节数组
            byte[] postBytes = encoding.GetBytes(param);
            
            webRequest.ContentType = "application/x-www-form-urlencoded;";
            webRequest.ContentLength = postBytes.Length;
 
            using (Stream reqStream = webRequest.GetRequestStream())
            {
                reqStream.Write(postBytes, 0, postBytes.Length);
            }
            try
            {
                //尝试获得要请求的URL的返回消息
                webResponse = (HttpWebResponse)webRequest.GetResponse();
            }
            catch (Exception)
            {
                //出错后直接抛出
                throw;
            }
            finally
            {
                if (webResponse != null)
                {
                    //获得网络响应流
                    using (StreamReader responseReader = new StreamReader(webResponse.GetResponseStream(), encoding))
                    {
                        responseStr = responseReader.ReadToEnd();//获得返回流中的内容
                    }
                    webResponse.Close();//关闭web响应流
                }
            }
            return responseStr;
        }

 

encoding为服务器接收的编码,例如：Encoding.GetEncoding("GBK")等

param post请求的参数 param1=123&param2=中国&param3=abc 这样的格式，中文部分不用使用编码，方法内转成byte[]时
会进行编码。