ios - IOS捏合手势的手势绑定(bind)限制

Question

我正在使用捏合手势来缩小 imageVIew 现在我可以将限制设置为 Down 到该限制不会让用户缩小。我为此使用以下代码。

func handlePinch(recognizer : UIPinchGestureRecognizer)
    {
        imageView.transform = CGAffineTransformScale(imageView.transform,
                                                         recognizer.scale, recognizer.scale)

        recognizer.scale = 1.0
}

Answer 1

我使用一些静态变量完成了这个

var cumulativeScale:CGFloat = 1.0
var maxScale:CGFloat = 3.5
var minScale:CGFloat = 0.5

@IBAction func zoomingInAndOut(_ pinchGesture: UIPinchGestureRecognizer) {
        guard pinchGesture.view != nil else {return}

        if pinchGesture.state == .began || pinchGesture.state == .changed{
            if (cumulativeScale < maxScale && pinchGesture.scale > 1.0) {
                pinchGesture.view?.transform = (pinchGesture.view?.transform)!.scaledBy(x: pinchGesture.scale, y: pinchGesture.scale)
                cumulativeScale *= pinchGesture.scale
                pinchGesture.scale = 1.0
            }
            if (cumulativeScale > minScale && pinchGesture.scale < 1.0) {
                pinchGesture.view?.transform = (pinchGesture.view?.transform)!.scaledBy(x: pinchGesture.scale, y: pinchGesture.scale)
                cumulativeScale *= pinchGesture.scale
                pinchGesture.scale = 1.0
            }
        }
    }