iOS手势处理由UIGestureRecognizer控制，不同手势有这个类的不同子类处理，不同手势处理有不同的相关属性。
| 子类 | 描述 |
|---|---|
| UITapGestureRecognizer | 点击手势 |
| UIPanGestureRecognizer | 跟着手移动手势 |
| UIPinchGestureRecognizer | 缩放手势 |
| UIRotationGestureRecognizer | 旋转手势 |
| UISwipeGestureRecognizer | 轻扫手势 |
| UILongPressGestureRecognizer | 长按手势 |
| UIScreenEdgePanGestureRecognizer | 屏幕边缘滑动手势 |
手势处理的步骤一般：
- 初始化手势，并添加到需要手势的View中
- 添加手势回调方法
UITapGestureRecognizer
属性numberOfTapsRequired表示点击次数，属性numberOfTouchesRequired表示点击手指数。
var isChange = false
...
let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.tap(tap:)))
tap.numberOfTapsRequired = 2
...
imageView.addGestureRecognizer(tap)
...
@objc func tap(tap: UITapGestureRecognizer) {
let center = imageView.center
if isChange {
imageView.frame.size.width /= 2
imageView.frame.size.height /= 2
imageView.center = center
isChange = false
} else {
imageView.frame.size.width *= 2
imageView.frame.size.height *= 2
imageView.center = center
isChange = true
}
}
UIPanGestureRecognizer
let pan = UIPanGestureRecognizer(target: self, action: #selector(ViewController.pan(pan:)))
@objc func pan(pan: UIPanGestureRecognizer) {
if pan.state == .began || pan.state == .changed {
// 移动后的变化（变化值类似向量）
let translation = pan.translation(in: imageView.superview)
print(translation)
imageView.center = CGPoint(x: imageView.center.x + translation.x, y: imageView.center.y + translation.y)
// view移动后，把上一步的移动值变为0，否则移动值为递增
pan.setTranslation(CGPoint.zero, in: imageView.superview)
}
}
UIRotationGestureRecognizer
let rotation = UIRotationGestureRecognizer(target: self, action: #selector(ViewController.rotation(rotation:)))
@objc func rotation(rotation: UIRotationGestureRecognizer) {
if rotation.state == .began || rotation.state == .changed {
imageView.transform = CGAffineTransform(rotationAngle: rotation.rotation)
}
}
UISwipeGestureRecognizer
let swipe = UISwipeGestureRecognizer(target: self, action: #selector(ViewController.swipe(swipe:)))
swipe.direction = .up
swipe.numberOfTouchesRequired = 3
@objc func swipe(swipe: UISwipeGestureRecognizer) {
print("扫的方向：\(swipe.direction),扫的手指数：\(swipe.numberOfTouchesRequired)")
}
UILongPressGestureRecognizer
numberOfTouchesRequired 长按的指头数
minimumPressDuratio 长按最小时间（秒）
let long = UILongPressGestureRecognizer(target: self, action: #selector(ViewController.long(long:)))
long.numberOfTouchesRequired = 2
long.minimumPressDuration = 1
@objc func long(long: UILongPressGestureRecognizer) {
print("长按手势，长按字头数为\(long.numberOfTouchesRequired)")
}
UIScreenEdgePanGestureRecognizer
let screenEdge = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(ViewController.screenEdage(screenEdage:)))
screenEdge.edges = .left
@objc func screenEdage(screenEdage: UIScreenEdgePanGestureRecognizer) {
print("屏幕边缘滑动手势：\(screenEdage.edges)")
}
详细代码： GestureDemo
