XML字符串/数组比较

我正在尝试将"filename"answers"filesize"中的索引与"xml"中的匹配。它们包含文件大小和名称。我需要在if语句中匹配它们。我被卡住了，不知道如何继续。

    public static void APB()
    {
        ArrayList filename = new ArrayList();
        ArrayList filesize = new ArrayList();
        var directory = new DirectoryInfo(Directory.GetCurrentDirectory());
        var files= directory.GetFiles("*", SearchOption.AllDirectories);
        long fnd = 0;
        foreach (var file in files)
        {
            filename.Add(file.FullName);
            filesize.Add(fnd += file.Length);
        }
        ArrayList xml = new ArrayList();
        XmlTextReader reader = new XmlTextReader(dictonary.launcher);
        while (reader.Read())
        {
            switch (reader.NodeType)
            {
                case XmlNodeType.Element:
                    xml.Add(reader.Name);
                    while (reader.MoveToNextAttribute())
                    xml.Add(reader.Name + "=" + reader.Value);
                    break;
            }
        }
    }