将 xml 标记与文本框进行比较

我想读取我的xml，如果文本框中的文本与xml中的标记相同，我希望它导航到其他页面。

我的代码是：

     StorageFolder storageFolder = Package.Current.InstalledLocation;
        StorageFile storageFile = await storageFolder.GetFileAsync("Registeduser.xml");
        string xml = await FileIO.ReadTextAsync(storageFile, Windows.Storage.Streams.UnicodeEncoding.Utf8);
        var doc = XDocument.Parse(xml);
        StorageFolder pastaxml = Package.Current.InstalledLocation;
        pastaxml = await pastaxml.GetFolderAsync("users''1101046102''xml''");
        StorageFile login = await pastaxml.GetFileAsync("info.xml");
        string xmllogin = await FileIO.ReadTextAsync(login, Windows.Storage.Streams.UnicodeEncoding.Utf8);
        var xdoc = XDocument.Parse(xmllogin);
        var rootemail = xdoc.Root;
        var rootNode = doc.Root;
        foreach (var child in rootNode.Descendants("user"))
        {
            //Login is a class
            var objLogin = new Login
            {
                id = child.Element("id").Value,
                Email=child.Element("email").Value
            };
        }
        foreach (var logemail in rootemail.Descendants("info"))
        {
            //Info is a class
            var email = new Info
            {
               Email = logemail.Element("email").Value
            };
            Info info = new Info();
            if (txtemail.Text == info.Email.ToString())
            {
                this.Frame.Navigate(typeof(DashBoard));
            }
            else
            {
                MessageBox("Email ou password incorreta");
            }
        }

XML是：

    <info>
        <id>1101046102</id>
       <email>email@hotmail.com</email>
    </info>

和：

    <?xml version="1.0" encoding="utf-8" ?>
   <registeredUser>
      <user>
        <id>1101046102</id>
        <email>email@hotmail.com</email>
      </user>
   </registeredUser>

我想要的只是将registeduser中的电子邮件与info.xml中的电子邮件进行比较.xml。当我取消程序并单击进入下一页时，该程序不执行任何操作。我做错了什么？

bool isEqual = doc.Descendants("email").First().Value == 
               xdoc.Descendants("email").First().Value;