C#获取网页内容

using System.Net;
using System.IO;
using System.Text;

       
            //方法一：
            // Create a request for the URL.         
            WebRequest request = WebRequest.Create("http://www.hao123.com");
            // If required by the server, set the credentials.
            request.Credentials = CredentialCache.DefaultCredentials;
            // Get the response.
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            // Display the status.
            Response.Write(response.StatusDescription);
            // Get the stream containing content returned by the server.
            Stream dataStream = response.GetResponseStream();
            // Open the stream using a StreamReader for easy access.
            StreamReader reader = new StreamReader(dataStream,Encoding.Default);
            // Read the content.
            string responseFromServer = reader.ReadToEnd();
            // Display the content.
            Response.Write(responseFromServer);
            // Cleanup the streams and the response.
            reader.Close();
            dataStream.Close();
            response.Close();

            //方法二：
            WebClient client = new WebClient();

            // Add a user agent header in case the 
            // requested URI contains a query.

            client.Headers.Add("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");

            Stream data = client.OpenRead("http://www.hao123.com");
            StreamReader reader = new StreamReader(data,Encoding.Default);
            string s = reader.ReadToEnd();
            Response.Write(s);
            data.Close();
            reader.Close();
            
            //方法三：
             WebClient client = new WebClient();
            //client.DownloadFile("http://www.hao123.com","123.htm");
            string reply = client.DownloadString("http://www.hao123.com");
            Response.Write(reply);