UIGestureRecognizer 有许多子类，用于监听一些常见的手势事件，这些子类主要有：
1.UISwipeGestureRecognizer：滑动（快速移动）
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//滑动手势
let swipe = UISwipeGestureRecognizer(target: self, action: #selector(swipe(recognizer:)))
swipe.direction = .up
self.view.addGestureRecognizer(swipe)
}
@objc func swipe(recognizer:UISwipeGestureRecognizer) {
print("swipe swipe")
let point = recognizer.location(in: view)
print("滑动起点坐标（x:\(point.x), y:\(point.y)）")
}
}
打印结果：
swipe swipe
滑动起点坐标（x:196.0, y:336.666656494141）
注意1：如果 UISwipeGestureRecognizer 在不指定方向的时候，默认向右滑动才会触发事件。如果要指定方向，需要设置 direction 属性:
//表示监听滑动的方向为向上
swipe.direction = .up
如果希望各个方向都响应手势，定义不同方向的UISwipeGestureRecognizer，添加到被监听对象：
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//向上滑动手势
let swipeUp = UISwipeGestureRecognizer(target: self, action: #selector(swipe(recognizer:)))
swipeUp.direction = .up
self.view.addGestureRecognizer(swipeUp)
//向下滑动手势
let swipeDown = UISwipeGestureRecognizer(target: self, action: #selector(swipe(recognizer:)))
swipeDown.direction = .down
view.addGestureRecognizer(swipeDown)
}
@objc func swipe(recognizer:UISwipeGestureRecognizer) {
if recognizer.direction == .up {
print("这是向上滑动")
} else if recognizer.direction == .down {
print("这是向下滑动")
}
let point = recognizer.location(in: view)
print("滑动起点坐标（x:\(point.x), y:\(point.y)）")
}
}
打印结果：
这是向下滑动
滑动起点坐标（x:192.0, y:271.666656494141）
这是向上滑动
滑动起点坐标（x:212.33332824707, y:454.33332824707）
2.UIScreenEdgePanGestureRecognizer：边缘滑动
-
这个是
UISwipeGestureRecognizer的子类，与后者不同的时。UIScreenEdgePanGestureRecognizer只触发从边缘开始的划动操作，比如从左侧边缘开始向右滑动。 -
UIScreenEdgePanGestureRecognizer没有direction属性，增加了个edges属性。表示要响应哪个边缘的划动操作。可以是从左边缘向右滑动，或右边缘向左、上边缘向下、下边缘向上、或响应全部边缘滑动。
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let edgeSwipe = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(edgeSwipe(recognizer:)))
//从右边缘开始滑动
edgeSwipe.edges = .right
view.addGestureRecognizer(edgeSwipe)
}
@objc func edgeSwipe(recognizer:UIScreenEdgePanGestureRecognizer) {
if recognizer.edges == .right {
print("这是从右边开始滑动")
}
let point = recognizer.location(in: view)
print("滑动起点坐标（x:\(point.x), y:\(point.y)）")
}
}
3.UITapGestureRecognizer：轻点手势（点击）
- 可以通过 numberOfTouchesRequired 属性设置触摸点数，比如设置 2 表示必须两个手指触摸时才会触发
- 通过 numberOfTapsRequired 属性设置点击次数，单击设置为 1，双击设置为 2
- 如果一个控件既监听了单击事件也监听了双击事件，默认当双击事件触发的时候也同时会触发单击事件。如果想双击时不触发单击，需要通过 require(toFail:) 进行设置
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//单击
let singleTap = UITapGestureRecognizer(target: self, action: #selector(singleTap(recognizer:)))
singleTap.numberOfTapsRequired = 1
singleTap.numberOfTouchesRequired = 1
//双击
let doubleTap = UITapGestureRecognizer(target: self, action: #selector(doubleTap(recognizer:)))
doubleTap.numberOfTapsRequired = 2
doubleTap.numberOfTouchesRequired = 1
//声明单击事件需要双击事件检测失败后才会执行
singleTap.require(toFail: doubleTap)
view.addGestureRecognizer(singleTap)
view.addGestureRecognizer(doubleTap)
}
@objc func singleTap(recognizer:UITapGestureRecognizer) {
print("这是单击")
}
@objc func doubleTap(recognizer:UITapGestureRecognizer) {
print("这是双击")
}
}
4.UIPinchGestureRecognizer：捏合手势（两个手指进行放大缩小）
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let pinch = UIPinchGestureRecognizer(target: self, action: #selector(pinch(recognizer:)))
view.addGestureRecognizer(pinch)
}
@objc func pinch(recognizer:UIPinchGestureRecognizer) {
//实时获取捏合的比例
print("捏合比例:\(recognizer.scale)")
//获取两个触摸点的坐标
print(recognizer.location(ofTouch: 0, in: view))
print(recognizer.location(ofTouch: 1, in: view))
}
}
注意：模拟器测试捏合和旋转手势时，按住 option 键，再用触摸板或鼠标操作
5.UIRotationGestureRecognizer：旋转手势（两个手指进行旋转）
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let rotation = UIRotationGestureRecognizer(target: self, action:
#selector(rotation(recognizer:)))
view.addGestureRecognizer(rotation)
}
@objc func rotation(recognizer:UIRotationGestureRecognizer) {
//旋转的弧度转换为角度
print(recognizer.rotation*(180/CGFloat.pi))
}
}
6.UIPanGestureRecognizer：拖动手势
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let redView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
redView.backgroundColor = UIColor.red
redView.center = view.center
view.addSubview(redView)
let pan = UIPanGestureRecognizer(target: self, action:
#selector(pan(recognizer:)))
redView.addGestureRecognizer(pan)
}
@objc func pan(recognizer:UIRotationGestureRecognizer) {
let point = recognizer.location(in: view)
//设置矩形的位置
recognizer.view?.center = point
}
}
注意
- 通过 recognizer.view 我们可以直接得到触发事件的 view 对象
- 一个 GestureRecognizer 只能对应一个 view，所以每个 view 还是要分别使用各自的 GestureRecognizer
实例：
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let redView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
redView.backgroundColor = UIColor.red
redView.center = view.center
view.addSubview(redView)
let yellowView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
yellowView.backgroundColor = UIColor.yellow
view.addSubview(yellowView)
let pan1 = UIPanGestureRecognizer(target: self, action:
#selector(pan(recognizer:)))
redView.addGestureRecognizer(pan1)
let pan2 = UIPanGestureRecognizer(target: self, action:
#selector(pan(recognizer:)))
yellowView.addGestureRecognizer(pan2)
}
@objc func pan(recognizer:UIRotationGestureRecognizer) {
let point = recognizer.location(in: view)
//设置矩形的位置
recognizer.view?.center = point
}
}
7.UILongPressGestureRecognizer：长按
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let longPress = UILongPressGestureRecognizer(target: self, action:
#selector(longPress(recognizer:)))
view.addGestureRecognizer(longPress)
}
@objc func longPress(recognizer:UIRotationGestureRecognizer) {
if recognizer.state == .began {
print("长按响应开始")
} else {
print("长按响应结束")
}
}
}
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