UIWindow addSubview handle events - ios

Question

I want to build a custom alert by UIViewController and add its view as a subview to the current window. The view displays very well, but I can't handle any touch events.
I have tried many times to add a button to this viewcontroller and add a target. I have also tried adding a UITapGestureRecognizer and set view's userInteractionEnabled to true, but this also failed even when I cleared all subviews just left the button.
Have I missed something?
Here is the code:
CustomAlert Viewcontroller:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
self.view.backgroundColor = [UIColor clearColor];
backgroundView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
backgroundView.backgroundColor = [UIColor blackColor];
backgroundView.alpha = 0.5;
[self.view addSubview:backgroundView];
backImage = [[UIImageView alloc]initWithFrame:CGRectMake((self.view.frame.size.width - 300) / 2, (self.view.frame.size.height - 250) / 2, 300, 250)];
backImage.image = [UIImage imageNamed:#"AlertBackground"];
[self.view addSubview:backImage];
confirmButton = [[UIButton alloc]initWithFrame:CGRectMake( backImage.frame.origin.x + 100 , backImage.frame.origin.y + 250 - 40, 100, 26)];
[self.view addSubview:confirmButton];
[confirmButton addTarget:self action:#selector(confirmButtonClick:) forControlEvents:UIControlEventTouchUpInside];
confirmButton.backgroundColor = [UIColor redColor];
[confirmButton setTitle:#"click me" forState:UIControlStateNormal];
}
-(void)confirmButtonClick:(UIButton*)sender{
[self.view removeFromSuperview];
}
-(void)show{
UIWindow * window = (UIWindow*)[UIApplication sharedApplication].keyWindow;
[window addSubview:self.view];
}
Method call custom alert:
CustomAlert * alert = [[CustomAlert alloc]init];
[alert show];

Answer 1

Try to rewrite your -show{} method with these
UIWindow * window = (UIWindow*)[UIApplication sharedApplication].keyWindow;
[window.rootViewController.view addSubview:self.view];
UPDATE:
And if previous don't help, try to overwrite
-(void)show{
UIWindow * window = (UIWindow*)[UIApplication sharedApplication].keyWindow;
[window.rootViewController addChildViewController:self];
[window.rootViewController.view addSubview:self.view];
[self didMoveToParentViewController:window.rootViewController];
}
Those three methods establish parent-child relations.