internal virtual string ToString(bool urlencoded, IDictionary excludeKeys)
{
    int count = this.Count;
    if (count == 0)
    {
        return string.Empty;
    }
    StringBuilder builder = new StringBuilder();
    bool flag = (excludeKeys != null) && (excludeKeys["__VIEWSTATE"] != null);
    for (int i = 0; i < count; i++)
    {
        string key = this.GetKey(i);
        if (((!flag || (key == null)) || !key.StartsWith("__VIEWSTATE", StringComparison.Ordinal)) && (((excludeKeys == null) || (key == null)) || (excludeKeys[key] == null)))
        {
            string str3;
            if (urlencoded)
            {
                key = HttpUtility.UrlEncodeUnicode(key);
            }
            string str2 = (key != null) ? (key + "=") : string.Empty;
            ArrayList list = (ArrayList) base.BaseGet(i);
            int num3 = (list != null) ? list.Count : 0;
            if (builder.Length > 0)
            {
                builder.Append('&');
            }
            if (num3 == 1)
            {
                builder.Append(str2);
                str3 = (string) list[0];
                if (urlencoded)
                {
                    str3 = HttpUtility.UrlEncodeUnicode(str3);
                }
                builder.Append(str3);
            }
            else if (num3 == 0)
            {
                builder.Append(str2);
            }
            else
            {
                for (int j = 0; j < num3; j++)
                {
                    if (j > 0)
                    {
                        builder.Append('&');
                    }
                    builder.Append(str2);
                    str3 = (string) list[j];
                    if (urlencoded)
                    {
                        str3 = HttpUtility.UrlEncodeUnicode(str3);
                    }
                    builder.Append(str3);
                }
            }
        }
    }
    return builder.ToString();
}