Pro WPF in C# 2008: Windows Presentation Foundation with .NET 3.5, Second Edition

Understanding Routed Events

Every .NET developer is familiar with the idea of events—messages that are sent by an object (such as a WPF element) to notify your code when something significant occurs. WPF enhances the .NET event model with a new concept of event routing. Event routing allows an event to originate in one element but be raised by another one. For example, event routing allows a click that begins in a toolbar button to rise up to the toolbar and then to the containing window before it's handled by your code.

Event routing gives you the flexibility to write tight, well-organized code that handles events in the most convenient place. It's also a necessity for working with the WPF content model, which allows you to build simple elements ...