Display a view or splash screen before applicationDidEnterBackground (to avoid active view screenshot)

Question

I have confidential informations in my app, so I would like to hide them with a splash screen when the app is about to be moved to background.

I do run the app on iO

Answer 1

Had the same issue, essentially I was using applicationDidEnterBackground to show a UIWindow on top of the content, but in iOS8 it didn't work as it did in iOS7.

The solution I found was to create the UIWindow in applicationWillResignActive but make it hidden securityWindow.hidden = YES; and then in applicationDidEnterBackground all I would do would be to change securityWindow.hidden = NO.

This seems to work exactly as iOS7 obscuring the content when multi tasking without affecting the view when using NotificationCenter or ControlPanel.

Answer 2

Need to write the code as follows:

-(void)applicationWillResignActive:(UIApplication *)application
{
    imageView = [[UIImageView alloc]initWithFrame:[self.window frame]];
    [imageView setImage:[UIImage imageNamed:@"Portrait(768x1024).png"]];
    [self.window addSubview:imageView];
}

Here to remove the imageview:

- (void)applicationDidBecomeActive:(UIApplication *)application
{
    if(imageView != nil) {
        [imageView removeFromSuperview];
        imageView = nil;
    }
}

It is working and properly tested.

Answer 3

Swift 3.0 Answer for those who are to lazy to translate.

func applicationDidEnterBackground(_ application: UIApplication) {

    let imageView = UIImageView(frame: self.window!.bounds)
    imageView.tag = 101
    imageView.image = ...

    UIApplication.shared.keyWindow?.subviews.last?.addSubview(imageView)
 }

func applicationWillEnterForeground(_ application: UIApplication) {

    if let imageView : UIImageView = UIApplication.shared.keyWindow?.subviews.last?.viewWithTag(101) as? UIImageView {
        imageView.removeFromSuperview()
    }

}

Answer 4

I think this will help for Swift 3.0

func applicationWillResignActive(_ application: UIApplication) {

        let imageView = UIImageView(frame: self.window!.bounds)
        imageView.tag = 101
        imageView.backgroundColor = UIColor.white
        imageView.contentMode = .center
        imageView.image = #image#
        UIApplication.shared.keyWindow?.subviews.last?.addSubview(imageView)

    }

func applicationWillEnterForeground(_ application: UIApplication) {
        ReachabilityManager.shared.stopMonitoring()
        if let imageView : UIImageView = UIApplication.shared.keyWindow?.subviews.last?.viewWithTag(101) as? UIImageView {
            imageView.removeFromSuperview()
        }
    }

Answer 5

Don't know why, but none of the methods described here worked for me. I was simply trying to cover the screen for security reasons. So, what helped was a Technical Q&A from Apple: https://developer.apple.com/library/ios/qa/qa1838/_index.html

I guess the main difference is using a UIViewController? Anyways, the following code works perfectly for me on IOS 9.1:

- (void)applicationDidEnterBackground:(UIApplication *)application
{     
    UIViewController *blankViewController = [UIViewController new];
    blankViewController.view.backgroundColor = [UIColor blackColor];

    [self.window.rootViewController presentViewController:blankViewController animated:NO completion:NULL];
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{
    [self.window.rootViewController dismissViewControllerAnimated:NO completion:NO];
}

Answer 6

@interface MyAppDelegate ()
@property (strong, nonatomic) MySplashView *splashView;
@end
@implementation MyAppDelegate
- (void)applicationWillResignActive:(UIApplication *)application {
    // hide keyboard and show a splash view
    [self.window endEditing:YES];
    MySplashView *splashView = [[MySplashView alloc] initWithFrame:self.window.bounds];
    [self.window addSubview:splashView];
    self.splashView = splashView;
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
    // remove the splash view
    if (self.splashView) {
        [self.splashView removeFromSuperview];
        self.splashView = nil;
    }
}
@end