1、Touch事件

//系统自动调用

//一个UITouch代表一根手指 按住option变成两根手指

//虽然是两个手指，但只执行一次触摸事件

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {} 开始触摸事件

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {} 手指移动事件

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {} 结束触摸时间

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {} 取消触摸手势

//获取任意手指

UITouch * touch = [touches anyObject];

//手指触摸的View

NSLog(@"touch.view:%@",touch.view);

//点击次数

NSLog(@"点击次数:%ld",touch.tapCount);

//当前手指的位置

CGPoint currentPonit = [touch locationInView:touch.view];

//上一次手指所处的位置

CGPoint previousPonit = [touch previousLocationInView:touch.view];

2、事件分发

事件产生和传递的过程：

当发生触摸事件的时候，先传递给UIApplication，以队列结构接收事件。传递给主窗口，主窗口传递给控制器的UIView,遍历UIView的子视图，寻找最合适的UIView来接收。

响应者链：

该类的上一级如果是UIView,子视图处理事件，如果处理不了，找他的父视图。

该类的上一级如果是UIViewController,则是由所属的控制器来处理。

//返回最合适的UIView

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {}

//判断当前的点在不在View上

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {

return YES;

}

3、UIImageView点击事件

self.imageView.userInteractionEnabled = NO;

//无法响应事件的3种情况：

//1、当userInteractionEnabled未开启

//2、当hidden属性为YES

//3、当alpha属性为0时

//将以YellowView为坐标系的点，转化为以button为坐标系的点 self = yellowView

CGPoint buttonPoint = [self convertPoint:point toView:self.button];

这个函数的用处是判断当前的点击或者触摸事件的点是否在当前的view中。

它被hitTest:withEvent:调用，

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event;   // default returns YES if point is in bounds

4、手机摇一摇

//事件的种类

- (void)motionBegan:(UIEventSubtype)motion withEvent:(nullable UIEvent *)event {

if (motion == UIEventSubtypeMotionShake) {

NSLog(@"摇一摇");

}

}

5、**Gesture手势

UIGestureRecognizerState：

开始： UIGestureRecognizerStateBegan

改变： UIGestureRecognizerStateChanged

结束： UIGestureRecognizerStateEnded

取消： UIGestureRecognizerStateCancelled

失败： UIGestureRecognizerStateFailed,

//同时使用两个手势 捏合 旋转

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {

return YES;

}

（1）点击手势 Tap

（2）长按手势 LongPress

    UILongPressGestureRecognizer * longGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longAction:)];

（4）捏合事件 Pinch

UIPinchGestureRecognizer * pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchAction:)];

pinchGesture.delegate = self;

[self.imageView addGestureRecognizer:pinchGesture];

self.pin = pinchGesture;

//对应事件

- (void)pinchAction:(UIPinchGestureRecognizer *)pin {

self.imageView.transform = CGAffineTransformScale(self.imageView.transform, pin.scale, pin.scale);

//复位

pin.scale = 1;

}

（5）旋转事件 Rotation

UIRotationGestureRecognizer * rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationAction:)];

rotationGesture.delegate = self;

[self.imageView addGestureRecognizer:rotationGesture];

//对应事件

- (void)rotationAction:(UIRotationGestureRecognizer *)rotation {

self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, rotation.rotation);

//复位

rotation.rotation = 0;

}

（6）拖动手势 Pan

UIPanGestureRecognizer * panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panAction:)];

[self.imageView addGestureRecognizer:panGesture];

//对应事件

- (void)panAction:(UIPanGestureRecognizer *)pan {

//获取拖动的偏移量

CGPoint ponit = [pan translationInView:self.view];

self.imageView.center = CGPointMake(self.imageView.center.x + ponit.x, self.imageView.center.y + ponit.y);

//复位

[pan setTranslation:CGPointZero inView:self.imageView];

}