C# POST请求demo，contentType 格式：application/x-www-form-urlencoded

/*

• url:为请求地址

• postData:请求内容例如："key1=value1&key2=value2&key3=value3"
  */
  public static string PostUrl(string url, string postData)
  {
  string result = "";
  try
  {
  HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);

          req.Method = "POST";
  
          req.ContentType = "application/x-www-form-urlencoded";
  
          req.Timeout = 800;//请求超时时间
  
          byte[] data = Encoding.UTF8.GetBytes(postData);
  
          req.ContentLength = data.Length;
  
          using (Stream reqStream = req.GetRequestStream())
          {
              reqStream.Write(data, 0, data.Length);
  
              reqStream.Close();
          }
  
          HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
  
          Stream stream = resp.GetResponseStream();
  
          //获取响应内容
          using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
          {
              result = reader.ReadToEnd();
          }
      }catch(Exception e){}
  
      return result;
  

  }