iPhone应用程序上的动画关闭，如相机应用程序上的快门

Question

I'd like my app to do an animation just before close, exactly like the official Camera app from Apple, that "closes the shutter" before closing itself. Is is possible or is this a private and undocumented API?

Thank you in advance!

Answer 1

There is no official way for your app to delay its closing after the user taps the home button. Apple wants users to be able to quit out of apps quickly and at anytime. However, you do get notified when your app is closing, and you do get a chance to run some code. I can't tell you for sure of any UI stuff would work, but the spot to try it is in your UIApplicationDelegate (AppDelegate) class. The methods you're interested in are:

- (void)applicationWillResignActive:(UIApplication *)application {
    // Try some UI stuff here
}

Or:

- (void)applicationDidEnterBackground:(UIApplication *)application {

}

I'm assuming the UI will change as the app window is animating away. Let us know if it works!