Objective -c, removeFromSuperview not works every time - ios

Question

I am trying to remove a view, sometimes it works fine , and sometimes not. I am beginner. I don't know what the problem. I am frustrated. Please let me know what the problem.my code :
-(void)hideNotification
{
btnNotification.selected=NO;
btnHome.selected=YES;
[notificationScreen.view removeFromSuperview];
notificationScreen=nil;
isNotificationScreen=NO;
}
I have also tried : dispatch_async(dispatch_get_main_queue(), ^{
[notificationScreen.view removeFromSuperview];
}); and performSelectorOnMainThread:#selector(removeFromSuperview) withObject:nil waitUntilDone:NO]; but not succeeded.

Answer 1

First and foremost thing I would check in this situation is to ensure updating my UI only on main thread. Trusting, you have already tried that out.
Next, per Apple Documentation, I would ensure following things:
If the view’s superview is not nil, the superview releases the view.
Never call this method from inside your view’s drawRect: method.
Finally, unsure how your notificationScreen object looks like, I would try to set a tag on the view to be removed and remove it based on the tag value. Not sure if notificationScreen refers to your current view controller in which your above code will now work. Try this out:
Set the tag of the view that you want to be removed
(myNotificationView.tag = 1) when initializing and adding to its parent view.
When you are ready to remove the notification view, do it like this
for (UIView *view in [self.view subviews] ) {
if (view.tag == 1 ) {
[view removeFromSuperview];
}
}
For step 2, you could have a strong reference to your notification view and call removeFromSuperview on that object.

Answer 2

First you need to check your view is subview or not. Just change code like below:
-(void)hideNotification
{
btnNotification.selected=NO;
btnHome.selected=YES;
if([notificationScreen.view isDescendantOfView:self.view]){
[notificationScreen.view removeFromSuperview];
}
notificationScreen=nil;
isNotificationScreen=NO;
}