Prevent next event handler being called

Question

I have two event handlers wired up to a button click in a Windows form like so:

this.BtnCreate.Click += new System.EventHandler(new RdlcCreator().FirstHandler);
         


        

Answer 1

Why don't you just replace them with one eventhandler? Something like this:

var rdlc = new RdlcCreator();
this.BtnCreate.Click += (sender, e) => {
    rdlc.FirstHandler(sender, e);
    if (!rdlc.HasHandledStuff) { // <-- You would need some kind of flag 
        this.BtnCreate_Click(sender, e);
    }
};

That way you can also guarantee the order of the handlers. Alternatively, use the above implementation, but change the signature of FirstHandler to return a bool indicating the condition (as in this case it doesn't really need to have the event's signature anymore):

    if (!rdlc.FirstHandler(sender, e)) { 
        this.BtnCreate_Click(sender, e);
    }

EDIT: OR, you just pass the second handler to FirstHandler.
Change the signature of FirstHandler to this:

void FirstHandler(object sender, EventArgs e, EventHandler nextHandler) {
    if (ConditionSatisfied) {
        // do stuff
    }
    else if (nextHandler != null) {
        nextHandler(sender, e);
    }
}

and then:

this.BtnCreate.Click += 
    (s, e) => new RdlcCreator().Firsthandler(s, e, this.BtnCreate_Click);