#199 – An Application’s Windows Property Lists All of Its Windows

The Application class has a Windows property which is a collection of all of the windows that have been created by the current application.

Assume that we have an application with a main window that includes the following two buttons:

Whenever the user clicks on the Create New Window button, we create and show a new window.

    private void btnCreate_Click(object sender, System.Windows.RoutedEventArgs e)
    {
        AnotherWindow win = new AnotherWindow();
        win.Title = DateTime.Now.ToLongTimeString();
        win.Show();
    }

In the Click event handler for the Where Are the Windows? button, we can iterate through all of the windows that the application created and display some information about each one.

        private void btnWhere_Click(object sender, RoutedEventArgs e)
        {
            StringBuilder sb = new StringBuilder();
            foreach (Window w in App.Current.Windows)
            {
                sb.AppendFormat("Window [{0}] is at ({1},{2}).\n", w.Title, w.Top, w.Left);
            }

            MessageBox.Show(sb.ToString(), "My Windows");
        }

The final result: