HttpWebRequest post请求的一个例子

using System;
using System.IO;
using System.Collections;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;
using System.Net;
using System.Text;

namespace WebApplication1
{

    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class Handler1 : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("http://fanyi.baidu.com/transcontent");
            Encoding encoding = Encoding.UTF8;
            string param = "ie=utf-8&source=txt&query=hello&t=1327829764203&token=8a7dcbacb3ed72cad9f3fb079809a127&from=auto&to=auto";
            //encoding.GetBytes(postData);
            byte[] bs = Encoding.ASCII.GetBytes(param);
            string responseData = String.Empty;            
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            req.ContentLength = bs.Length;
            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(bs, 0, bs.Length);
                reqStream.Close();
            }
            using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
            {
                using (StreamReader reader = new StreamReader(response.GetResponseStream(),encoding))
                {
                    responseData = reader.ReadToEnd().ToString();
                }
                context.Response.Write(responseData);
            }
        }
        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}