Why moving parent view is not moving subview? - ios

Question

I have a view as follow:
In my code I want to move this view keyboard size:
-(void) keyboardWillShow:(NSNotification *) notification {
NSDictionary* keyboardInfo = [notification userInfo];
// Work out where the keyboard will be
NSValue* keyboardFrameBegin = [keyboardInfo valueForKey:UIKeyboardFrameBeginUserInfoKey];
CGRect keyboardFrameBeginRect = [keyboardFrameBegin CGRectValue];
// Work out animation duration
NSTimeInterval animationDuration =[[keyboardInfo valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
UIViewAnimationOptions keyboardAnimationCurve = [[keyboardInfo valueForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
// Animate this
[UIView animateWithDuration:animationDuration
delay:0.0
options:keyboardAnimationCurve
animations:^(){
self.view.frame = CGRectOffset(self.view.frame, 0, -keyboardFrameBeginRect.size.height);
}
completion:NULL];
}
It is moving everything to top except child views. Then I tried to move child views to the top as follow:
-(void) keyboardWillShow:(NSNotification *) notification {
NSDictionary* keyboardInfo = [notification userInfo];
// Work out where the keyboard will be
NSValue* keyboardFrameBegin = [keyboardInfo valueForKey:UIKeyboardFrameBeginUserInfoKey];
CGRect keyboardFrameBeginRect = [keyboardFrameBegin CGRectValue];
// Work out animation duration
NSTimeInterval animationDuration =[[keyboardInfo valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
UIViewAnimationOptions keyboardAnimationCurve = [[keyboardInfo valueForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
// Animate this
[UIView animateWithDuration:animationDuration
delay:0.0
options:keyboardAnimationCurve
animations:^(){
self.view.frame = CGRectOffset(self.view.frame, 0, -keyboardFrameBeginRect.size.height);
self.memberNumberLayout.frame = CGRectOffset(self.memberNumberLayout.frame, 0, -keyboardFrameBeginRect.size.height);
}
completion:NULL];
}
self.memberNumberLayout is a subview of main UIView. But it is not moving. What could force sub view to stay there? Could it be because of constrains? As you can see to subviews and one label has not move with their parent view!
Constrains

Answer 1

While it is really hard to tell the problem from your constraints hierarchy screenshots, I think the problem is related to top constraints for self.memberNumberLayout my suggestions are the following:
1- use constrains instead of frames to animate your views by using IBOutlet from the top constraints of the container view then use the constant e.g self.containerConstraint.constant = keyboardSize * -1;
2- use scrollviews for such problems. UIScrollView is a great view for moving views up when keyboard appears or disappears, also this is can be very helpful when you run your app on different devices. Refer to this question for more information: How to make a UITextField move up when keyboard is present?

Answer 2

The problem is that you are saying self.view.frame =. You can't do that — this view is fixed as a subview of the window. Give self.view a content view the same size at itself (pinned to all four sides), with all other views inside it, and when the time comes, move the content view. Moreover, you've got constraints on these views (auto layout), so you must not change the frame of the content view; to move it, change its constraints.