在平常生活中，我们发表文章，网站的链接老是很长，特别是淘宝的那种链接，更是长的离谱，特别不友好，故现在开始推短链接这种应用。 原理： 其实很简单，短链接商，把你的长连接存到他的数据库中，然后根据GUID生成一个唯一标识的短链接，这个链接是请求的他们的服务器。当别人访问这个短链接的时候，短链接商就从服务器上把你的长链接读出来，然后直接跳转到你的长链接地址。 难点： 主要还是模拟POST、GET请求。其他还是比较简单的。 我做了个百度的长链接转短链接的例子。新浪和腾讯的由于需要OAuth授权，这块目前还没有接触过，不太了解，以后了解吧。 我把我做的简单的demo贴出来。 HttpRequestHelper 作用：模拟HTTP的POST GET请求的 [code lang="csharp"] public class HttpRequestHelper { #region 同步通过POST方式发送数据 /// <summary> /// 通过POST方式发送数据 /// </summary> /// <param name="Url">url</param> /// <param name="postDataStr">Post数据</param> /// <param name="cookie">Cookie容器</param> /// <returns></returns> public static string SendDataByPost(string Url, string postDataStr, ref CookieContainer cookie) { HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url); if (cookie.Count == 0) { request.CookieContainer = new CookieContainer(); cookie = request.CookieContainer; } else { request.CookieContainer = cookie; } request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; request.ContentLength = postDataStr.Length; Stream myRequestStream = request.GetRequestStream(); StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312")); myStreamWriter.Write(postDataStr); myStreamWriter.Close(); 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; } #endregion #region 同步通过GET方式发送数据 /// <summary> /// 通过GET方式发送数据 /// </summary> /// <param name="Url">url</param> /// <param name="postDataStr">GET数据</param> /// <param name="cookie">GET容器</param> /// <returns></returns> public static string SendDataByGET(string Url, string postDataStr, ref CookieContainer cookie) { HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url + (postDataStr == "" ? "" : "?") + postDataStr); if (cookie.Count == 0) { request.CookieContainer = new CookieContainer(); cookie = request.CookieContainer; } else { request.CookieContainer = cookie; } 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; } #endregion } [/code] JsonHelper 作用：Json转换成对象 [code lang="CSharp"] public class JsonHelper { /// <summary> /// JSON格式字符转换为T类型的对象 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="jsonStr"></param> /// <returns></returns> public static T ParseFormByJson<T>(string jsonStr) { T obj = Activator.CreateInstance<T>(); using (System.IO.MemoryStream ms = new System.IO.MemoryStream(System.Text.Encoding.UTF8.GetBytes(jsonStr))) { System.Runtime.Serialization.Json.DataContractJsonSerializer serializer = new System.Runtime.Serialization.Json.DataContractJsonSerializer(typeof(T)); return (T)serializer.ReadObject(ms); } } } [/code] BaiduLink 请求百度返回的json数据的实体 [code lang="CSharp"] public class BaiduLink { string _longurl; /// <summary> /// 长链接 /// </summary> public string longurl { get { return _longurl; } set { _longurl = value; } } string _status; /// <summary> /// 返回状态 /// </summary> public string status { get { return _status; } set { _status = value; } } string _tinyurl; /// <summary> /// 短链接 /// </summary> public string tinyurl { get { return _tinyurl; } set { _tinyurl = value; } } } [/code] 具体实现的代码： [code lang="CSharp"] //参考链接：http://www.baidu.com/search/dwz.html private void btnBaiDu_Click(object sender, EventArgs e) { /* 生成短网址 请求：向dwz.cn/create.php发送post请求，发送数据包括url=长网址 返回：json格式的数据 status!=0 出错，查看err_msg获得错误信息（UTF-8编码） 成功，返回生成的短网址 tinyurl字段 */ string longlink = tbLongLink.Text.Trim(); CookieContainer cookieContainer = new CookieContainer(); string result = HttpRequestHelper.SendDataByPost("http://dwz.cn/create.php", "url=" + longlink, ref cookieContainer); //{"longurl":"http:\/\/www.baidu.com\/s?tn=baiduhome_pg","status":0,"tinyurl":"http:\/\/dwz.cn\/2Up1h"} BaiduLink modelResult=JsonHelper.ParseFormByJson<BaiduLink>(result); tbShortLink.Text = modelResult.tinyurl; } [/code] 我把自己找的相关的资料贴出来：   1、百度长链接转短链接的API文档：http://www.baidu.com/search/dwz.html 2、新浪长链接转短链接的API文档：http://open.weibo.com/wiki/Short_url/shorten 3、腾讯长链接转短链接的API文档：http://wiki.open.t.qq.com/index.php/API%E6%96%87%E6%A1%A3/%E5%85%B6%E4%BB%96/%E7%9F%ADurl%E5%8F%98%E9%95%BFurl