public MainWindow()
{
InitializeComponent();
AdditionalInitializeComponent();
VisualInitializeComponent();
var loginWindow = new LoginWindow();
loginWindow.ShowDialog();
if (!loginWindow.DialogResult.HasValue || loginWindow.DialogResult != true)
{
Close();
return;
}
Login = loginWindow.GetLogin();
SideMenu.Login = Login;
SideMenu.LvlVisual();
TopMenu.Login = Login;
TopMenu.LvlVisual();
PageSwitcher.Switch(new StartPage()); // Страница по умолчанию
}