HOW to Detect window closing event in AIR application and how to prevent

Question

My question is how can I prevent the user from closing the application?. I need an alert message to appear that asks the user if he really want to leave the application. My application is developed in Adobe AIR. Please help, I am in trouble.

Answer 1

Yeah, I had a doozy finding this too. But it really is quite simple to intercept and prevent the close.

Beware that this code will prevent standard window closing only! I don't recommend using it without adding the confirmation dialogue or close code in place of the comment.

stage.nativeWindow.addEventListener(Event.CLOSING, onCloseCall);

function onCloseCall(evt:Event):void
{
    evt.preventDefault();
    //Show dialogue here.
}

Now, how to show the alert message (a.k.a. dialogue box) depends entirely on your platform, method, and needs. For example, if you use Flash Professional, a custom movieclip that you hide and show might do the trick. However, if you use Flex, there are means of creating a modal dialogue. Research that separately.