获取url参数

public string getremovedURL(string can) {
        string url = Request.Url.ToString();
        int index = url.IndexOf(can);
        string removrurl = "";
            if (url.IndexOf("&", index) > -1)
                removrurl = url.Substring(index, url.IndexOf("&", index) - index + 1);
            else
                removrurl = url.Substring(index - 1);
        return url.Replace(removrurl,"");
    }

public string getURL(string can, string val)
    {
        val = Server.UrlEncode(val);
        string url = Request.Url.ToString();
        string removrurl = "";
        int index = url.IndexOf(can);
        if (index == -1)
        {
            if (url.IndexOf('?') > 0)
                removrurl = "&" + can + val;
            else
                removrurl = "?" + can + val;
            url += removrurl;
        }
        else
        {
            if (url.IndexOf("&", index) > -1)
                removrurl = url.Substring(index, url.IndexOf("&", index) - index + 1);
            else