UIImageView 捏缩放 swift [英] UIImageView pinch zoom swift

问题描述

我希望有人可以帮助我.我试图允许用户在 UIImageView 上捏缩放(允许最大和最小级别).但由于某种原因，它不能正常工作.图像放大一点然后反弹回来.谢谢.

I was hoping someone could help me out. I am trying to allow a user to pinch zoom on a UIImageView(with a max and min level allowed). But for some reason the it does not work right. The image zooms a little then just bounces back. Thank you.

这是缩放功能

func zoom(sender:UIPinchGestureRecognizer) {


    if sender.state == .Ended || sender.state == .Changed {

        let currentScale = self.view.frame.size.width / self.view.bounds.size.width
        var newScale = currentScale*sender.scale

        if newScale < 1 {
            newScale = 1
        }
        if newScale > 9 {
            newScale = 9
        }

        let transform = CGAffineTransformMakeScale(newScale, newScale)

        self.imageView?.transform = transform
        sender.scale = 1

    }

}

推荐答案

我决定将 imageView 添加到 UIScrollView.它允许用户缩放和平移.这是我使用的代码.

I decided to add the imageView to a UIScrollView. It allows the user to zoom and pan over. Here is the code I used.

为了设置我使用的最大/最小缩放:

in order to set max/min zoom I used :

    scrollImg.minimumZoomScale = 1.0
    scrollImg.maximumZoomScale = 10.0

这里是其余的代码.

    var vWidth = self.view.frame.width
    var vHeight = self.view.frame.height

    var scrollImg: UIScrollView = UIScrollView()
    scrollImg.delegate = self
    scrollImg.frame = CGRectMake(0, 0, vWidth!, vHeight!)
    scrollImg.backgroundColor = UIColor(red: 90, green: 90, blue: 90, alpha: 0.90)
    scrollImg.alwaysBounceVertical = false
    scrollImg.alwaysBounceHorizontal = false
    scrollImg.showsVerticalScrollIndicator = true
    scrollImg.flashScrollIndicators()

    scrollImg.minimumZoomScale = 1.0
    scrollImg.maximumZoomScale = 10.0

    defaultView!.addSubview(scrollImg)

    imageView!.layer.cornerRadius = 11.0
    imageView!.clipsToBounds = false
    scrollImg.addSubview(imageView!)

我也必须添加这个

func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
    return self.imageView
}

斯威夫特 3 &以上函数原型

func viewForZooming(in scrollView: UIScrollView) -> UIView? {
    return self.mainImage
}

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