URL参数GB2312和UTF-8编码 自动识别

网上找的，以备后用。

直接上代码：

public static string QueryStringDecode(string key)
        {
            HttpRequest Request = System.Web.HttpContext.Current.Request;

            if (Regex.IsMatch(
                HttpUtility.UrlDecode(Request.Url.Query, Encoding.GetEncoding("iso-8859-1")),
                @"^(?:[x00-x7f]|[xfc-xff][x80-xbf]{5}|[xf8-xfb][x80-xbf]{4}|[xf0-xf7][x80-xbf]{3}|[xe0-xef][x80-xbf]{2}|[xc0-xdf][x80-xbf])+$"
            ))
            {
                return Request.QueryString[key];
            }
            else
            {
                System.Collections.Specialized.NameValueCollection Rq = HttpUtility.ParseQueryString(Request.Url.Query, System.Text.Encoding.GetEncoding("gb2312"));
                return Rq[key];
            }
        }