How to implement a cancel event in C#

Question

I know that in C#, there are several built in events that pass a parameter ("Cancel") which if set to true will stop further execution in the object that raised the event.

How would you implement an event where the raising object was able to keep track of a property in the EventArgs?

Here is a WinForms example of what I am trying to do:
http://msdn.microsoft.com/en-us/library/system.componentmodel.canceleventargs.cancel.aspx

Thank you.

Answer 1

Easy:

1. Create an instance of CancelEventArgs (or your custom type).
2. Raise the event, passing that instance.
3. Check the Canceld property on [1].

Do you need code samples?

Answer 2

It's really easy.

private event _myEvent;

// ...

// Create the event args
CancelEventArgs args = new CancelEventArgs();

// Fire the event
_myEvent.DynamicInvoke(new object[] { this, args });

// Check the result when the event handler returns
if (args.Cancel)
{
    // ...
}

Answer 3

You have to wait the call that raise the event and then check the flag in your EventArgs (in particular CancelEventArgs).