SquishIt.Framework.CSS.CSSAssetsFileHasher.AppendQueryStringPairValue C# (CSharp) Method

        static string AppendQueryStringPairValue(string url, string key, string value)
        {
            var path = url;
            var queryString = string.Empty;

            var queryStringPosition = url.IndexOf('?');

            if (queryStringPosition > -1)
            {
                path = url.Substring(0, queryStringPosition);
                queryString = url.Substring(queryStringPosition);
            }

            var querystring = HttpUtility.ParseQueryString(queryString);

            querystring.Add(key, value);

            var querystringwithAppendedValue = FlattenedQueryString(querystring);

            if (!string.IsNullOrEmpty(querystringwithAppendedValue))
            {
                querystringwithAppendedValue = "?" + querystringwithAppendedValue;
            }

            return path + querystringwithAppendedValue;
        }