UIView - Animate with duration seems to ignore duration

Question

I'm facing a problem : I have a very simple custom UIView which groups one UITextField and one UILabel.

The UILabel is on the UITextField, and I want that the UILabel go up to 40px when user begins to edit the UITextField.

I'm using constraints to set the textfield's frame and the label's frame.

So I just set the delegate in my custom view with UITextFieldDelegate protocol, and implement the delegate method : textFieldDidBeginEditing, as bellow :

I'm just animating the constraint (center Y) of my label in the delegate method.

func textFieldDidBeginEditing(textField: UITextField) {
    self.centerVerticallyLabelConstraint.constant = -40
    UIView.animateWithDuration(0.5) {
        self.textFieldLabel.layoutIfNeeded()
    }
}

What happens is that the UILabel goes up correctly, but it goes up instantly. It ignores the duration of 0.5 in my animation. I don't know why :

I'm not animating something else at the same time, I only have this animation. I haven't disable animations for UIView. The delegate is set to my UITextfield.

Any idea?

score 11 · Accepted Answer · edited Jul 04 '19 at 15:13

11

Try calling layoutIfNeeded on your view instead of textview.

UIView.animate(withDuration: 0.5) {
    self.view.layoutIfNeeded()
}

Hope this helps.

edited Jul 04 '19 at 15:13

Karen Hovhannisyan

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answered Sep 13 '16 at 11:59

nishith Singh

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Thank you... I'm angry to haven't see this before ! – AnthonyR Sep 13 '16 at 12:03
I have been struggling with this for a day. In my case I was animating height constraint of a view, and I was animating it from the view itself. I didn't think at all I had to call the -layoutIfNeeded on the superview. Thank you. – Matteo Gobbi Dec 11 '19 at 00:30

score 0 · Answer 2 · edited Jul 03 '19 at 07:52

0

Try Below code to execute:

func textFieldDidBeginEditing(textField: UITextField) {
    UIView.animate(withDuration: 0.5) {
        self.textFieldLabel.frame.origin.y -= 40
    }
}

edited Jul 03 '19 at 07:52

Karen Hovhannisyan

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2
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31

answered Sep 13 '16 at 12:02

Lawrence413

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1

This will break autolayout constraints, which may be undesired. Animating constraints is a valid thing to do. – Losiowaty Sep 13 '16 at 12:08

score 0 · Answer 3 · answered Sep 13 '16 at 12:12

0

need to call self.view.layoutIfNeeded() not self.textFieldLabel.layoutIfNeeded() Thanks

answered Sep 13 '16 at 12:12

Jagveer Singh

2,258
19
34

score 0 · Answer 4 · answered Nov 21 '19 at 22:58

For me, the issue seems to be because I was already on the main thread & I called the animation block inside a GCD main.async call.

ie I had

DispatchQueue.main.async { 

<# update the constraint s#>

self.animatedViewsParent.setNeedsLayout() 
animatedView.setNeedsLayout()

UIView.animate(withDuration: 2.0) {
    self.animatedViewsParent.layoutIfNeeded()
  }
}

The view animates moves but does not animate gradually over 2.0 seconds. Removing the outer DispatchQueue.main.async {} solves the problem.

UIView - Animate with duration seems to ignore duration

4 Answers4