Prevent iOS from taking screen capture of app before going into background

Question

You all might know that iOS takes a screen shot of your application before throwing it into the background. This is usually for a better User experience like quick animation

Answer 1

swift 4.0 version.

for use custom icon

first add this line at top of AppDelegate

var imageView: UIImageView?

and add this:

func applicationDidEnterBackground(_ application: UIApplication) {
    imageView = UIImageView(frame: window!.frame)
    imageView?.image = UIImage(named: "AppIcon")
    window?.addSubview(imageView!)
}

func applicationWillEnterForeground(_ application: UIApplication) {
    if imageView != nil {
        imageView?.removeFromSuperview()
        imageView = nil
    }
}

background with black color

func applicationDidEnterBackground(_ application: UIApplication) {
    let blankViewController = UIViewController()
    blankViewController.view.backgroundColor = UIColor.black
    window?.rootViewController?.present(blankViewController, animated: false)
}

func applicationWillEnterForeground(_ application: UIApplication) {
    window?.rootViewController?.dismiss(animated: false)
}