根据 scrollview 使用自动布局水平滚动更改视图的高度和宽度

Question

容器视图层次结构：-

容器视图
- 滚动视图
  - 左视图
  - 查看中心
  - 右视图
- 浮动底部视图

我需要根据 scrollview 水平滚动更改 FloatingBottomView 的 height 和 width 约束。

初始出口：-

@IBOutlet weak var constantFloatingBottomViewWidth: NSLayoutConstraint! // 300
@IBOutlet weak var constantFloatingBottomViewHeight: NSLayoutConstraint! // 70

override func viewWillAppear(_ animated: Bool) {
         self.scrollView.contentOffset.x = self.view.bounds.width
         // view center in scrollview
}

func scrollViewDidScroll(_ scrollView: UIScrollView) {
     if scrollView.contentOffset.x < self.view.bounds.width {
        // when scrollview move view center to view left, constantFloatingBottomViewWidth and height goes to down at some point  
     }
     else if scrollView.contentOffset.x > self.view.bounds.width {
       // when scrollview move view left to view center, constantFloatingBottomViewWidth & height goes up to same point range while it down and back to original constantFloatingBottomViewWidth and height
     }
}

我尝试过使用这种方式在 scrollViewDidScroll 方法中获得一些比例。从左到右快速滚动或反之亦然没有得到准确的输出

let scale =  abs(scrollView.contentOffset.x / self.view.bounds.width)
            print("scale:=\(scale)")

Answer 1

我认为你需要像这样给按钮动画

为此，您无需做任何事情，只需向按钮添加动画即可，如下所示在 viewDidLoad

中调用 setupButtonanimation

 func setupButtonAnimation()
        {
            let animation = CABasicAnimation.init(keyPath: "transform.scale")
            animation.fromValue = 1.0
            animation.toValue = 0.45
            animation.duration = 1.0
            //Set the speed of the layer to 0 so it doesn't animate until we tell it to
            self.btn1.layer.speed = 0.0;
            self.btn1.layer.add(animation, forKey: "transform");
        }
        func scrollViewDidScroll(_ scrollView: UIScrollView)
        {
            let screenSize = self.view.bounds.size
            if let btn =  self.btn1
            {
                var factor:CGFloat = 1.0
                factor = scrollView.contentOffset.x / screenSize.width
                if factor > 1
                {
                        factor = 2 - factor
                }
                print(factor)
                //This will change the size
                let timeOffset = CFTimeInterval(1-factor)
                btn.layer.timeOffset = timeOffset
               }
        }

根据 scrollview 使用自动布局水平滚动更改视图的高度和宽度

Change height and width of view according to scrollview scroll horizontally using auto layout

uiscrollview

swift

ios-autolayout

swift3