How to close a startup window

Question

I have C# WPF application that has a login windows as it's startup URI. I want to close the the startup window, which is the login window when the combination of username and password is correct.

I have this code

var username = query.username;
var password = query.password;

if (userTexbox.Text == username.ToString() && passwordbox.Password == password.ToString())
{
    var entity = new Log
    {
        user = userTexbox.Text,
        dateTime = DateTime.Now.ToString()
    };
    logCollection.Insert(entity);

    Mainwindow main = new MainWindow();
    this.Close();
}
else
{
    MessageBox.Show("User not found/Wrong credentials", "Re-enter Credentials");
}

But even with the Close() method, the login window is still visible although not active.

Answer 1

Change the logic: set the main window as startup window, then display the login window from main window. Check the bellow code, it's for the main window's contructor:

...
public MainWindow()
{
    InitializeComponent();

    //--init main windows minimized
    WindowState = System.Windows.WindowState.Minimized;

    Loaded +=
        delegate
        {
            //hide main window
            Hide();

            //initialize the login window
            var loginWin = new LoginWindow
            {
                WindowStartupLocation = System.Windows.WindowStartupLocation.CenterScreen,
                WindowStyle = System.Windows.WindowStyle.SingleBorderWindow,
            };

            loginWin.Closed += delegate
            {
                //check login result (OK)
                if (loginWin.Result != LoginResult.Success)
                    Application.Current.Shutdown(1);

                //--display the main window
                Show();
                WindowState = System.Windows.WindowState.Normal;
                Focus();
            };

            //show&focus the login
            loginWin.Show();
            loginWin.Focus();
        };
}
...

I hope it helps.

EDIT

Here the LoginWindow code behind.

public partial class LoginWindow : Window
{
    public LoginResult Result { get; private set; }

    public LoginWindow()
    {
        InitializeComponent();
    }

    private void ButtonLogin_OnClick(object sender, RoutedEventArgs e)
    {
        //example login button
        Result = DoLogin();
        Close();
    }

    private LoginResult DoLogin()
    {
        //NOTE: Add your login logic here (for now sucess response)
        return LoginResult.Success;
    }
}

public enum LoginResult
{
    Unknow,
    Success,
    Failed
}

Answer 2

What you are missing here is Assignment of MainWindow

Application.Current.MainWindow = main;

After creating new instance of MainWindow if you assign it the Application.Current.MainWindow (before closing the login window) then it has a main window to continue the STA thread and the LoginWindow thread can be released.

Do let me know if this helps.