Swift 3 UIView animation

问题:

Since upgrading my project to swift 3 my autolayout constraint animations aren't working; to be more specific, they're snapping to the new position rather than animating.

UIView.animate(withDuration: 0.1,
               delay: 0.1,
               options: UIViewAnimationOptions.curveEaseIn,
               animations: { () -> Void in
                   constraint.constant = ButtonAnimationValues.YPosition.DefaultOut()
                   self.layoutIfNeeded()
    }, completion: { (finished) -> Void in
    // ....
})

I know they added the UIViewPropertyAnimator class but am yet to try it.

回答1:

I had this problem too with the newest update to swift 3.

To be exact, whenever you want to animate the view, you actually call layoutIfNeeded on the superview of that view.

Try this instead:

UIView.animate(withDuration: 0.1,
           delay: 0.1,
           options: UIViewAnimationOptions.curveEaseIn,
           animations: { () -> Void in
               constraint.constant = ButtonAnimationValues.YPosition.DefaultOut()
               self.superview?.layoutIfNeeded()
}, completion: { (finished) -> Void in
// ....
})

It seems in the past they've been lenient about being able to just relayout the view you want to animate. But its in the documentation that you should really be calling layoutIfNeeded in the superview.

回答2:

Upgrade to swift 3.0

View right to left animation like apple default push animation

//intially set x = SCREEN_WIDTH
view.frame = CGRect(x: ScreenSize.SCREEN_WIDTH, y: ScreenSize.SCREEN_HEIGHT - heightTabBar , width: ScreenSize.SCREEN_WIDTH, height: heightTabBar)

UIView.animate(withDuration: 0.50, delay: 0.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 0, options: [], animations: {
 //Set x position what ever you want
                        view.frame = CGRect(x: 0, y: ScreenSize.SCREEN_HEIGHT - heightTabBar , width: ScreenSize.SCREEN_WIDTH, height: heightTabBar)

                    }, completion: nil)

回答3:

First set the new value for your constraint and then call animate.

self.YOUR_CONSTRAINT.constant = NEW_VALUE
UIView.animate(withDuration: 1.0) {
    self.view.layoutIfNeeded()
}

回答4:

Swift 3.1 , Xcode 8.3.2

This code works well for me. Any changes on your view will animate in slow motion.

UIView.animate(withDuration: 3.0, animations: { // 3.0 are the seconds

// Write your code here for e.g. Increasing any Subviews height.

self.view.layoutIfNeeded()

})

回答5:

Swift 4, Xcode 10

Right to Left animation for search

//intially set x = Your_View_Width

    viewOfSearch.frame = CGRect(x: viewOfSearch.frame.size.width, y: 0 , width: viewOfSearch.frame.size.width, height: 50)

    UIView.animate(withDuration: 0.50, delay: 0.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 0, options: [], animations: {
        //Set x position what ever you want
        self.viewOfSearch.frame = CGRect(x: 0, y: 0 , width: self.viewOfSearch.frame.size.width, height: 50)

    }, completion: nil)