如何实现可取消的事件？

In System.ComponentModel, there's a class called CancelEventArgs which contains a Cancel member that can be set in event listeners. The documentation on MSDN explains how to use that to cancel events from within a listener, but how do I use it to implement my own cancelable events? Is there a way to check the Cancel member after each listener fires, or do I have to wait until after the event has fired all its listeners?In System.ComponentModel, there's a class calle