iOS UIScrollView和控制器返回手势冲突解决方法
时间：2022-04-23 08:45:09 | 栏目：iOS代码 | 点击：次
开发中，有部分UI，会将UIScrollView横向铺在底层，上面放tableView 或一些视图左右滚动切换，底层的scrollView会和Nav ViewController原有的返回手势冲突
解决办法，重写UIScrollView 的gestureRecognizerShouldBegin,在ScrollView滚动到头的时候，屏蔽ScrollView的手势
class GesturesConflictScrollView: UIScrollView {
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
back(by: gestureRecognizer)
}
private final func back(by gestureRecognizer: UIGestureRecognizer) -> Bool {
guard gestureRecognizer == panGestureRecognizer else { return true }
// point.x < 0 代表左滑即手指从屏幕右向左移动 反之一样
let point: CGPoint = panGestureRecognizer.translation(in: self)
let state: UIGestureRecognizer.State = gestureRecognizer.state
let locDistance: CGFloat = UIScreen.main.bounds.size.width
if state == .began || state == .possible {
let locationPoint = gestureRecognizer.location(in: self)
if point.x > 0 && locationPoint.x < locDistance && contentOffset.x <= 0 {
return false
}
let pageCount = contentSize.width / UIScreen.main.bounds.size.width
let criticalPoint = pageCount < 2 ? locDistance : locDistance * (pageCount - 1)
if point.x < 0 && contentOffset.x == criticalPoint {
return false
}
}
return true
}
}