Animating frame occasionally works

Question

Here's my function that animates my view

func animateViewMoving (up:Bool, moveValue :CGFloat) {

    let movementDuration:NSTimeInterval = 0.3
    let movement:CGFloat = ( up ? -moveValue : moveValue)
    self.view.setNeedsLayout()
    UIView.animateWithDuration(movementDuration, animations: {
    self.view.layoutIfNeeded()
    self.view.frame.origin.y += movement
    })

}

I call this function on these two functions of UITextFieldDelegate

func textFieldDidBeginEditing(textField: UITextField) {

        animateViewMoving(true, moveValue: 200)

}

func textFieldDidEndEditing(textField: UITextField) {

        animateViewMoving(false, moveValue: 200)

}

The problem is this- Whenever I run my build and open the view for the first time, the view shifts up on pressing the textField and shifts down when editing the textField ends. However if I go back to a previous view and enter the view again, the view does not shift up on pressing the textField. Why is animateWithDuration working irregularly?

Answer 1

Sorry I don't know swift so I'll just write my solution in objective-C.

I assume that you are using AutoLayout. If that's the case I suggest that when you animate a view, you animate it's constraints, not the frame of the view. I encountered a lot of problems before when I animate the frame of the view.

Here's a sample:

- (void)moveSubview
{
    _subviewLeadingSuperLeading.constant = 20; //just a sample to move the subview horizontally.

    [UIView animateWithDuration:0.5 animations:^
     {
         [self.view layoutIfNeeded];
     }

     completion:^(BOOL isFinished)
     {
         //Do whatever you want
     }];
}

I hope this will help you. :)