Xamarin个人资料页面

Question

我想为用户登录时创建一个用户个人资料，以便查看其用户名和其他内容。我相信我做得正确，但是有问题。 当我尝试通过Login方法将数据添加到_name和_class时，不要添加数据。

这是登录页面：

public partial class LoginPage : Rg.Plugins.Popup.Pages.PopupPage
{
    SQLiteConnection _sqlconnection = DependencyService.Get<ISQLiteConnection>().GetConnection();
    Users _user = new Users();
    public string _name = "name";
    public string _class = "class";
    SQLiteManager manager;
    public LoginPage ()
    {
        InitializeComponent ();
        manager = new SQLiteManager();
    }

    private async void btnLogin_Clicked(object sender, EventArgs e)
    {
        var username = txtName.Text;
        var password = txtPassword.Text;
        var loginState = Login(username, password);

        if (loginState)
        {
            if (txtName.Text != null || txtPassword.Text != null)
            {
                await Navigation.PushModalAsync(new StartPage());
                await PopupNavigation.Instance.PopAsync();
            }
            else
            {
                await DisplayAlert("ERROR", "You can't leave it blank.", "OK");
            }
        }
        else if (!loginState)
        {
            await DisplayAlert("ERROR", "There is no user", "OK");
            await PopupNavigation.Instance.PopAsync();
        }
    }

    public bool Login(string Username, string Password)
    {
        string mySelectQuery = "SELECT Count(*) FROM Users WHERE Name='" + Username + "' AND Password='" + Password + "'";
        string getId = "SELECT Id FROM Users WHERE Name='" + Username + "' AND Password='" + Password + "'";

        var user = _sqlconnection.CreateCommand(mySelectQuery);
        var Id = _sqlconnection.CreateCommand(getId);

        var count = user.ExecuteScalar<int>();
        var id = Id.ExecuteScalar<int>();           
        if (count > 0)
        {               
            return true;
        }

        var profileUser = manager.Get6(id);
        _name = profileUser.Name;
        _class = profileUser.Class;

        return false;
    }

    private async void btnCancel_Clicked(object sender, EventArgs e)
    {
        await PopupNavigation.Instance.PopAsync();
    }
}

以及此处的个人资料页面：

public partial class DetailPage3 : ContentPage
{
    LoginPage _login = new LoginPage();
    public DetailPage3 ()
    {
        InitializeComponent ();
        lblName.Text = _login._name;
        lblClass.Text = _login._class;
    }
}