Ralph Arvesen (vertigo blog)

public MainWindow()
{
    InitializeComponent();

    // subscribe to events raised by any child, Child Control is a Button in this example
    this.AddHandler(Button.ClickEvent, new RoutedEventHandler(ChildClicked));
}
        
private void ChildClicked(object sender, RoutedEventArgs e)
{
    // called when event is raised by any child
}

<Window x:Class="WpfEvents.MainWindow"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:controls="clr-namespace:WpfEvents"
  Title="WPF Events" Height="200" Width="200"
  Button.Click="ChildClicked">

// hooking up events requires a reference to each control
this.ChildControl1.Click += new RoutedEventHandler(ChildControl1_Click);
this.ChildControl2.Click += new RoutedEventHandler(ChildControl2_Click);
this.ChildControl3.Click += new RoutedEventHandler(ChildControl3_Click);
this.ChildControl4.Click += new RoutedEventHandler(ChildControl4_Click);

• There is only one instance of the Events class in the application.
• It contains a list of global events and helper methods to raise the events.
• Any object can subscribe to events.
• Any object can raise events.
• That means the main page can handle events from any child control, children can handle events from the main page, and siblings can handle events from each other.
• A reference to the control is not required to handle events.
  

public static class Events
{
    // example global event that can be handled by any object in the application
    public static event EventHandler ChildControlClicked;
    public static void RaiseChildControlClicked(object sender, EventArgs args)
    {
        if (ChildControlClicked != null)
        {
            ChildControlClicked(sender,args);
        }
    }
}

// raise global event
Events.RaiseChildControlClicked(this, EventArgs.Empty);

public Page()
{
    InitializeComponent();
    
    // subscribe to global event
    Events.ChildControlClicked += new System.EventHandler(Events_ChildControlClicked);
}

private void Events_ChildControlClicked(object sender, System.EventArgs e)
{
    // called when the event is raised, it could be raised by
    // any object in the application, this object does not need
    // a reference to the object that raised the event
}