c#获取url请求的返回值

  public string GetInfo(string url)
        {

            string strBuff = "";

            Uri httpURL = new Uri(url);

            ///HttpWebRequest类继承于WebRequest，并没有自己的构造函数，需通过WebRequest的Creat方法 建立，并进行强制的类型转换   

            HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(httpURL);

            ///通过HttpWebRequest的GetResponse()方法建立HttpWebResponse,强制类型转换  

 
            HttpWebResponse httpResp = (HttpWebResponse)httpReq.GetResponse();

            ///GetResponseStream()方法获取HTTP响应的数据流,并尝试取得URL中所指定的网页内容   

                ///若成功取得网页的内容，则以System.IO.Stream形式返回，若失败则产生ProtoclViolationException错 误。在此正确的做法应将以下的代码放到一个try块中处理。这里简单处理   

            Stream respStream = httpResp.GetResponseStream();

            ///返回的内容是Stream形式的，所以可以利用StreamReader类获取GetResponseStream的内容，并以 

  
            //StreamReader类的Read方法依次读取网页源程序代码每一行的内容，直至行尾（读取的编码格式：UTF8）

   
            StreamReader respStreamReader = new StreamReader(respStream, Encoding.UTF8);

            strBuff = respStreamReader.ReadToEnd();

            return strBuff;

        }

        public static String SendRequest(String url, Encoding encoding)
        {
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);

            webRequest.Method = "GET";

            HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse();

            StreamReader sr = new StreamReader(webResponse.GetResponseStream(), encoding);

            //StreamReader sr = new StreamReader(webResponse.GetResponseStream(), Encoding.GetEncoding(encoding));

            return sr.ReadToEnd();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string url = "地址栏";

            string result = SendRequest(url, Encoding.Default);

            button2.Text = result;

        }