c# url传参根据ascii码排序

public static string GetSign(Hashtable dataht)
{
string sign = "";
ArrayList akeys = new ArrayList(dataht.Keys);
akeys.Sort();
foreach (string skey in akeys)
{
sign += skey + "=" + dataht[skey] + "&";
}
sign = sign.TrimEnd('&');
return sign;
}