[2013.9.24]贴吧客户端sign的算法。。。

static void Main(string[] args)
{
    Dictionary<string, string> map
      = new Dictionary<string, string>();
    map.Add("name1", "value1");
    map.Add("name2", "value2");
    //...
    StringBuilder poststr = new StringBuilder();
    StringBuilder tosign = new StringBuilder();
    foreach (var elem in map)
    {
        poststr.Append(elem.Key).Append("=")
               .Append(HttpUtility.UrlEncode(elem.Value, Encoding.UTF8))
               .Append("&");
        tosign.Append(elem.Key).Append(elem.Value);
    }
    tosign.Append("tiebaclient!!!");
    poststr.Append("sign=").Append(MD5Encrypt(tosign.ToString(), Encoding.UTF8));
    Console.WriteLine(poststr.ToString());

}

static string MD5Encrypt(string text, Encoding enco)
{
    byte[] input = enco.GetBytes(text);
    MD5CryptoServiceProvider md5
      = new MD5CryptoServiceProvider();
    byte[] output = md5.ComputeHash(input);
    StringBuilder sb = new StringBuilder();
    foreach (byte x in output)
      sb.AppendFormat("{0:X2}", x);
    return sb.ToString();
}