C#模拟http 发送post或get请求的简单实例

private string HttpPost(string Url, string postDataStr) 
    { 
      HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url); 
      request.Method = "POST"; 
      request.ContentType = "application/x-www-form-urlencoded"; 
      request.ContentLength = Encoding.UTF8.GetByteCount(postDataStr); 
      request.CookieContainer = cookie; 
      Stream myRequestStream = request.GetRequestStream(); 
      StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312")); 
      myStreamWriter.Write(postDataStr); 
      myStreamWriter.Close(); 
  
      HttpWebResponse response = (HttpWebResponse)request.GetResponse(); 
  
      response.Cookies = cookie.GetCookies(response.ResponseUri); 
      Stream myResponseStream = response.GetResponseStream(); 
      StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8")); 
      string retString = myStreamReader.ReadToEnd(); 
      myStreamReader.Close(); 
      myResponseStream.Close(); 
  
      return retString; 
    } 
  
    public string HttpGet(string Url, string postDataStr) 
    { 
      HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url + (postDataStr == "" ? "" : "?") + postDataStr); 
      request.Method = "GET"; 
      request.ContentType = "text/html;charset=UTF-8"; 
  
      HttpWebResponse response = (HttpWebResponse)request.GetResponse(); 
      Stream myResponseStream = response.GetResponseStream(); 
      StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8")); 
      string retString = myStreamReader.ReadToEnd(); 
      myStreamReader.Close(); 
      myResponseStream.Close(); 
  
      return retString; 
    }

在post的时候有时也用的到cookie，像登录163发邮件时候就需要发送cookie，所以在外部一个cookie属性随时保存 CookieContainer cookie = new CookieContainer();

注意：有时候请求会重定向，但我们就需要从重定向url获取东西，像QQ登录成功后获取sid，但上面的会自动根据重定向地址跳转。我们可以用：

request.AllowAutoRedirect = false;设置重定向禁用，你就可以从headers的Location属性中获取重定向地址