Getting U+fffd/65533 instead of special character from Query String

Question

I have a C# .net web project that have a globalization tag set to:

Answer 1

    public string GetEncodedQueryString(string key)
    {
        string query = Request.QueryString[key];
        if (query != null)
            if (query.Contains((char)0xfffd))
                query = HttpUtility.ParseQueryString(Request.Url.Query, Encoding.GetEncoding("iso-8859-1"))[key];
        return query;
    }