解码：
HttpUtility.UrlDecode(Request.Cookies["flyxnet"].Value
写入时编码
Response.Cookies["flyxnet"].Value = HttpUtility.UrlEncodeUnicode(voteMsg);
解码：
HttpUtility.UrlDecode(Request.Cookies["flyxnet"].Value
写入时编码
Response.Cookies["flyxnet"].Value = HttpUtility.UrlEncodeUnicode(voteMsg);