How to access MainWindow's variables from second Window

Question

Is there another way to access MainWindow's public variables than :

MainWindow mainWindow = Application.Current.Windows.OfType<MainWindow>().FirstOrDefault();
mainWindow.variable....

this work fine, but I'm creating a WPF application and integrating a USB Webcam to my project and using this code above to access MainWindow's variables. This causes some problems like program is still running when I close MainWindow and camera won't stop. Any suggestions?

Answer 1

This is an over simplified example for what i wrote in comments(you really should look at mvvm the example below is not mvvm).

public class SelectedIndexData
{
    public int SelectedIndex { get; set; }
}

public partial class MainWindow : Window
{

    private readonly SelectedIndexData _selectedIndexData = new SelectedIndexData();
    public MainWindow()
    {
        InitializeComponent();
    }


    private void ComboBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        _selectedIndexData.SelectedIndex = ComboBox.SelectedIndex;
    }


    private void ShowChildWindow(object sender, RoutedEventArgs e)
    {
       new ChildWindow(_selectedIndexData).Show();
    }
}

public partial class ChildWindow : Window
{
    private SelectedIndexData _selectedIndexData;
    public ChildWindow(SelectedIndexData selectedIndexData)
    {
        InitializeComponent();
        _selectedIndexData = selectedIndexData; // do whatever you want with your data here

    }
}