import UIKitclass ViewController: UIViewController { //屏幕的宽 let kscreenwidth = UIScreen.main.bounds.size.width //屏幕的高 let kscreenheight = UIScreen.main.bounds.size.height override func viewDidLoad() { super.viewDidLoad() //UIScrollView:滚动视图，是所有滚动视图的基类，只要一个视图能够滚动，要么是UIScrollView，要是UIScrollView的子类，UIScrollView有两个很重要子类：UITableView,UICollectionView //什么时候才需要滚动：当我们的内容大于可视区域时，为了看到更多内容，才需要滚动去查看 //创建UIScrollView let scrollview = UIScrollView(frame: CGRect(x: 20, y: 20, width: kscreenwidth - 40, height: kscreenheight - 40)) scrollview.backgroundColor = #colorLiteral(red: 0.9098039269, green: 0.4784313738, blue: 0.6431372762, alpha: 1) //设置scrollview的内容区域大小 scrollview.contentSize = CGSize(width: 3*kscreenwidth, height: 2*kscreenheight) let imageview = UIImageView(frame: CGRect(x: 0, y: 0, width: 3*kscreenwidth, height: 2*kscreenheight)) imageview.image = #imageLiteral(resourceName: "image.jpg") //设置scrollview的偏移量 //scrollview.contentOffset = CGPoint(x: kscreenwidth, y: 0) scrollview.addSubview(imageview) //设置滚动条样式 scrollview.indicatorStyle = .white //设置是否显示滚动条 scrollview.showsVerticalScrollIndicator = false //水平滚动条 scrollview.showsHorizontalScrollIndicator = false //方向锁,滚动的时候只能朝一个方向滚动 scrollview.isDirectionalLockEnabled = true //设置是否有弹簧效果 //scrollview.bounces = false //设置是否总是有水平方向有弹簧效果 scrollview.alwaysBounceHorizontal = true //设置是否总是有垂直方向有弹簧效果 scrollview.alwaysBounceVertical = true //设置是否支持整页滚动 scrollview.isPagingEnabled = true //设置scrollview是否支持滚动 //scrollview.isScrollEnabled = false //设置scrollView是否支持回到顶部 scrollview.scrollsToTop = true //scrollview的代理属性 scrollview.delegate = self //设置scrollView的最大最小缩放比例 scrollview.minimumZoomScale = 1.0 self.view.addSubview(scrollview) } } //在延展中管理UIScrollViewDelegate的协议方法 extension ViewController:UIScrollViewDelegate{ //1当scrollView滚动的时候这个方法会持续触发 func scrollViewDidScroll(_ scrollView: UIScrollView) {// any offset changes print("滚动着，滚动着") print(scrollView.contentOffset) } //2缩放的过程中持续触发 func scrollViewDidZoom(_ scrollView: UIScrollView){ // any zoom scale changes // called on start of dragging (may require some time and or distance to move) print("缩放着") print(scrollView.zoomScale) } //3开始拖拽的时候触发 func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {// called on finger up if the user dragged. velocity is in points/millisecond. targetContentOffset may be changed to adjust where the scroll view comes to rest print("开始拖拽了") } //4将要结束拖拽的时候触发 func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer)
{// called on finger up if the user dragged. decelerate is true if it will continue moving afterwards
print("要结束拖拽了")
}
//5已经结束拖拽的时候触发
func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool){
print("结束拖拽")
}
//6将要开始减速的时候触发
func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView){ // called on finger up as we are moving
print("将要开始减速")
}
//7减速完成，速度为0，这个方法很重要，往往都是在这个方法中获取scrollView偏量
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {// called when scroll view grinds to a halt
print("减速完成")
}
//8给scrollView设置一个结束动画的时候触发，不制定动画就不会触发
func scrollViewDidEndScrollingAnimation(_ scrollView: UIScrollView) {// called when setContentOffset/scrollRectVisible:animated: finishes. not called if not animating
}
//9返回scrollView上缩放视图
func viewForZooming(in scrollView: UIScrollView) -> UIView? {// return a view that will be scaled. if delegate returns nil, nothing happens
return scrollView.viewWithTag(200)
}
//10将要开始缩放的时候触发
func scrollViewWillBeginZooming(_ scrollView: UIScrollView, with view: UIView?) {// called before the scroll view begins zooming its content
print("将要开始缩放的时候触发")
}
//11结束缩放的时候触发
func scrollViewDidEndZooming(_ scrollView: UIScrollView, with view: UIView?, atScale scale: CGFloat) {// scale between minimum and maximum. called after any 'bounce' animations
print("结束缩放的时候触发")
}
//12设置点就状态栏是否能回到顶部
func scrollViewShouldScrollToTop(_ scrollView: UIScrollView) -> Bool {// return a yes if you want to scroll to the top. if not defined, assumes YES
return true
}
//13scrollView回到顶部的触发的方法
func scrollViewDidScrollToTop(_ scrollView: UIScrollView){ // called when scrolling animation finished. may be called immediately if already at top
print("scrollView已经回到顶部")
}
}
// override func didReceiveMemoryWarning() {
// super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
// }
//}