Question

How can I launch an event that has accessors like this :

public event EventHandler CanExecuteChanged     {       add       {         CommandManager.RequerySuggested += value;       }       remove       {         CommandManager.RequerySuggested -= value;       }     } 

If it were a normal event I would launch it by:

CanExecuteChanged(sender, EventArgs..).  

But here it doesn’t work – I can only do

CanExecuteChanged +=.. 

to attach a method do the event – but I can’t Launch it.

Also some documentation on the subject would be appreciated. Thanks.

EDIT The event is from class implementing ICommand in WPF. there’s nothing more to show :). And no – the CommandManager.RequerySuggested(this, EventArgs.Empty); doesn’t work.

EDIT2 Not sure what to say – Jon’s example should have worked yet even if the add method is called correctly – when I try to call the event – it’s null :|. I probably will drop events with accessors.

Answer 1

That event is just subscribing to and unsubscribing from another event. If you want your subscribers (and only your subscribers – not separate ones to the other event) to be invoked, you’ll need to keep hold of your subscribers separately. For instance, you could change the code to something like:

private EventHandler canExecuteChanged;  public event EventHandler CanExecuteChanged {     add     {         CommandManager.RequerySuggested += value;         canExecuteChanged += value;     }     remove     {         CommandManager.RequerySuggested -= value;         canExecuteChanged -= value;     } }