获取其它网站的title，显示乱码

获取其它网站的title内容，但结果有的显示正确，有的显示为乱码我是这样写的：protected void Page_Load(object sender, EventArgs e)
    {
        HttpWebRequest hwr = (HttpWebRequest)HttpWebRequest.Create("http://www.google.cn/music/homepage");//要获取的url
        HttpWebResponse hwre;
        try
        {
            hwre = (HttpWebResponse)hwr.GetResponse();
            using (Stream s = hwre.GetResponseStream())
            {
                Encoding encoding = Encoding.Default;
                string ContentType = hwre.ContentType.Trim();
                if (ContentType.IndexOf("utf-8") != -1)
                    encoding = Encoding.UTF8;
                else if (ContentType.IndexOf("utf-7") != -1)
                    encoding = Encoding.UTF7;
                else if (ContentType.IndexOf("unicode") != -1)
                    encoding = Encoding.Unicode;
                using (StreamReader sr = new StreamReader(s, encoding))
                {
                    string strBody = sr.ReadToEnd();
                    Match m = Regex.Match(strBody, @"<title>(.*)</title>", RegexOptions.IgnoreCase);
                    Response.Write("标题：" + m.Groups[1]);
                }
            }
        }
        catch
        {
            Response.Write("获取标题失败！");
        }
    }