如何从左到右和向后缩放 UIView？

Question

我想让 UIView 在我按下按钮时从左向右缩放显示。如果我再次点击按钮，视图应该从右向左缩小。

我找到了如何从左到右执行此操作的说明，但即使是此解决方案也只能使用一次。如果我隐藏视图并再次播放动画，它会再次从中心缩放它。从右向左缩放它也不起作用，因为它会立即消失而没有任何动画。

到目前为止，这是我的代码：

if(!addQuestionaryView.isHidden)
    {
        //Reset input if view is hidden
        addQuestionaryInput.text = ""
        self.addQuestionaryView.isHidden = false
        let frame = addQuestionaryView.frame;
        let rect = CGRect(x: frame.origin.x, y: frame.origin.y, width: frame.width, height: frame.height)
        let leftCenter = CGPoint(x: rect.minX, y: rect.minY)
        addQuestionaryView.layer.anchorPoint = CGPoint(x:1,y: 0.5)
        addQuestionaryView.layer.position = leftCenter
        UIView.animate(withDuration: 0.6,
                       animations: {
                        self.addQuestionaryView.transform = CGAffineTransform(scaleX: 0, y: 1)
        },
                       completion: { _ in
                        self.addQuestionaryView.isHidden = true
        })
    }
    else
    {
        self.addQuestionaryView.isHidden = false
        let frame = addQuestionaryView.frame;
        let rect = CGRect(x: frame.origin.x, y: frame.origin.y, width: frame.width, height: frame.height)
        let leftCenter = CGPoint(x: rect.minX, y: rect.midY)
        addQuestionaryView.layer.anchorPoint = CGPoint(x:0,y: 0.5);
        addQuestionaryView.layer.position = leftCenter
        addQuestionaryView.transform = CGAffineTransform(scaleX: 0, y: 1)
        UIView.animate(withDuration: 0.6,
                       animations: {
                        self.addQuestionaryView.transform = CGAffineTransform(scaleX: 1, y: 1)
        },
                       completion: nil)
    }

如前所述，出现的部分工作一次，然后再次从中心开始。消失的部分根本不起作用

Answer 1

删除这个：

    addQuestionaryView.layer.anchorPoint = CGPoint(x:0,y: 0.5);
    addQuestionaryView.layer.position = leftCenter
    addQuestionaryView.transform = CGAffineTransform(scaleX: 0, y: 1)

然后在你的 animate with duration 块中使用下面的代码而不是 CGAfflineTransform

addQuestionaryView.frame = CGRect(0,0,500,100)

将 500 宽度替换为您想要的任何宽度。

要关闭它，请执行以下操作：

addQuestionaryView.frame = CGRect(0,0,0,100);

Answer 2

我不知道 "to scale it so it has a little look like Android reveal animations" 是什么意思（我希望我永远不会知道；我从未见过 Android phone，我从不希望看到一个）。

但是你的意思是这样的吗？这是通过在视图前面设置一个 mask 动画来完成的，从而显示然后隐藏它：

这是该示例中使用的代码：

class MyMask : UIView {
    override func draw(_ rect: CGRect) {
        let r = CGRect(x: 0, y: 0, width: rect.width/2.0, height: rect.height)
        UIColor.black.setFill()
        UIGraphicsGetCurrentContext()?.fill(r)
    }
}

class ViewController: UIViewController {

    @IBOutlet weak var lab: UILabel!
    var labMaskOrigin = CGPoint.zero

    var didAddMask = false
    override func viewDidLayoutSubviews() {
        if didAddMask {return}
        didAddMask = true
        let mask = MyMask()
        mask.isOpaque = false
        let w = self.lab.bounds.width
        let h = self.lab.bounds.height
        mask.frame = CGRect(x: -w, y: 0, width: w*2, height: h)
        self.lab.mask = mask
        self.labMaskOrigin = mask.frame.origin
    }

    var labVisible = false
    func toggleLabVisibility() {
        labVisible = !labVisible
        UIView.animate(withDuration: 5) {
            self.lab.mask!.frame.origin = self.labVisible ?
                .zero : self.labMaskOrigin
        }
    }
}

如何从左到右和向后缩放 UIView？

How to scale a UIView from left to right and back?

scaling

animation

ios

swift