代码如下:
  //Get请求方式
    private string RequestGet(string Url)
    {
        string PageStr = string.Empty;//用于存放还回的html
        Uri url = new Uri(Url);//Uri类 提供统一资源标识符 (URI) 的对象表示形式和对 URI 各部分的轻松访问。就是处理url地址
        try
        {
            HttpWebRequest httprequest = (HttpWebRequest)WebRequest.Create(url);//根据url地址创建HTTpWebRequest对象
            #region 参数设置
            httprequest.Method = "get";

            //---------------------------------------------设定一些参数（不必要可以）
            //httprequest.KeepAlive = false;//持久连接设置为false
            //httprequest.ProtocolVersion = HttpVersion.Version11;// 网络协议的版本
            //httprequest.Proxy = WebProxy.GetDefaultProxy();//服务器代理
            //httprequest.ContentType = "application/x-www-form-urlencoded";//http 头
            //httprequest.AllowAutoRedirect = true;
            //httprequest.MaximumAutomaticRedirections = 10;
            //httprequest.Timeout = 30000;//设定超时十秒（毫秒）
            //httprequest.UserAgent = "mozilla/4.0 (compatible; msie 6.0; windows nt 5.1)"; //浏览器
            //=================================================
            #endregion
            HttpWebResponse response = (HttpWebResponse)httprequest.GetResponse();//使用HttpWebResponse获取请求的还回值
            Stream steam = response.GetResponseStream();//从还回对象中获取数据流
            StreamReader reader = new StreamReader(steam, Encoding.GetEncoding("gb2312"));//读取数据Encoding.GetEncoding("gb2312")指编码是gb2312，不让中文会乱码的
            PageStr = reader.ReadToEnd();
            reader.Close();
        }
        catch (Exception e)
        {
            PageStr += e.Message;
        }
        return PageStr;
    }

代码如下:
//Post请求方式，于Get的方式写法相似，所以解释就些少一点了
 

  private string RequestPost(string Url,string Context)//两个参数分别是Url地址和Post过去的数据
    {
        string PageStr=string.Empty;
        Uri url = new Uri(Url);
        byte[] reqbytes=Encoding.ASCII.GetBytes(Context);
        try
        {
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "post";
            req.ContentType = "application/x-www-form-urlencoded";
            req.ContentLength = reqbytes.Length;
            Stream stm = req.GetRequestStream();
            stm.Write(reqbytes, 0, reqbytes.Length);

            stm.Close();
            HttpWebResponse wr = (HttpWebResponse)req.GetResponse();
            Stream stream = wr.GetResponseStream();
            StreamReader srd= new StreamReader(stream,Encoding.GetEncoding("gb2312"));
            PageStr += srd.ReadToEnd();
            stream.Close();
            srd.Close();
        }
        catch (Exception e)
        {
            PageStr += e.Message;
        }
        return PageStr;
    }

代码如下:
public string WebClientGet(string url)
        {
            var client = new WebClient();
            client.Headers.Add("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");
            var stream = client.OpenRead(url);
            if (stream == null) return "";
            var reader = new StreamReader(stream, Encoding.Default);
            var result = reader.ReadToEnd();
            stream.Close();
            reader.Close();
            return result;
        }