Вам нужно создать DependencyProperty, чтобы справиться с близко поведение окна:
DependencyProperty
namespace MyApp.DependencyProperties
{
public class WindowProperties
{
public static readonly DependencyProperty WindowClosingProperty =
DependencyProperty.RegisterAttached("WindowClosing", typeof(RelayCommand), typeof(WindowProperties), new UIPropertyMetadata(null, WindowClosing));
public static object GetWindowClosing(DependencyObject depObj)
{
return (RelayCommand)depObj.GetValue(WindowClosingProperty);
}
public static void SetWindowClosing(DependencyObject depObj, RelayCommand value)
{
depObj.SetValue(WindowClosingProperty, value);
}
private static void WindowClosing(DependencyObject depObj, DependencyPropertyChangedEventArgs e)
{
var element = (Window)depObj;
if (element != null)
element.Closing += OnWindowClosing;
}
private static void OnWindowClosing(object sender, CancelEventArgs e)
{
RelayCommand command = (RelayCommand)GetWindowClosing((DependencyObject)sender);
command.Execute((Window)sender);
}
}
}
В вашей ViewModel
public RelayCommand WindowClosedCommand { get; set; }
private void WindowClose()
{
Application.Current.Shutdown();
}
В конструкторе ViewModel
this.WindowCloseCommand = new RelayCommand(WindowClose);
В вашем XAML
<mah:MetroWindow x:Class="MyApp.Views.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mah="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro"
xmlns:dp="clr-namespace:MyApp.DependencyProperties"
dp:WindowProperties.WindowClosing="{Binding WindowClosedCommand}" />