手势识别器的使用

1.手势识别器的常用代理

 //是否允许开始触发手势
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
    return YES/NO;
}

// 是否允许同时支持多个手势，默认是不支持多个手势
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    return YES/NO;
}
 
//是否允许接收手指产生的手势事件
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
    // 获取当前的触摸点
    CGPoint curP = [touch locationInView:touch.view];
    //逻辑处理
    return YES/NO;
}

2.手势识别的状态

typedef NS_ENUM(NSInteger, UIGestureRecognizerState) {
    // 没有触摸事件发生，所有手势识别的默认状态
    UIGestureRecognizerStatePossible,
    // 一个手势已经开始但尚未改变或者完成时
    UIGestureRecognizerStateBegan,
    // 手势状态改变
    UIGestureRecognizerStateChanged,
    // 手势完成
    UIGestureRecognizerStateEnded,
    // 手势取消，恢复至Possible状态
    UIGestureRecognizerStateCancelled, 
    // 手势失败，恢复至Possible状态
    UIGestureRecognizerStateFailed,
    // 识别到手势识别
    UIGestureRecognizerStateRecognized = UIGestureRecognizerStateEnded
};

3.点按手势

- (void)setUpTap{
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)];
    //需要几根手机点击才能触发(默认是1)
    tap.numberOfTouchesRequired = 1;
    [_imageView addGestureRecognizer:tap];
}

- (void)tap:(UITapGestureRecognizer *)tap{
}

4.长按手势

- (void)setUpLongPress{
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
    [self.imageView addGestureRecognizer:longPress];
}
- (void)longPress:(UILongPressGestureRecognizer *)longPress{
    if (longPress.state == UIGestureRecognizerStateBegan) {
    }
}

5.轻扫手势

- (void)setUpSwipe{
    // 默认轻扫的方向是往右
    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe)];
    
    swipe.direction = UISwipeGestureRecognizerDirectionUp;
    [self.imageView addGestureRecognizer:swipe];
    // 如果以后想要一个控件支持多个方向的轻扫，必须创建多个轻扫手势，一个轻扫手势只支持一个方向
    // 默认轻扫的方向是往右
    UISwipeGestureRecognizer *swipeDown = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe)];
    swipeDown.direction = UISwipeGestureRecognizerDirectionDown;
    [self.imageView addGestureRecognizer:swipeDown];   
}
- (void)swipe{
}

6.旋转手势

- (void)setUpRotation{
    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)];
    rotation.delegate = self;
    [self.imageView addGestureRecognizer:rotation];
}

// 默认传递的旋转的角度都是相对于最开始的位置
- (void)rotation:(UIRotationGestureRecognizer *)rotation{
    self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, rotation.rotation);
    // 复位
    rotation.rotation = 0;
    // 获取手势旋转的角度
    NSLog(@"%f",rotation.rotation);
}

7.捏合手势

- (void)setUpPinch{
    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)];
    pinch.delegate = self;
    [self.imageView addGestureRecognizer:pinch];
}

- (void)pinch:(UIPinchGestureRecognizer *)pinch{
    self.imageView.transform = CGAffineTransformScale(self.imageView.transform, pinch.scale, pinch.scale);
    // 复位
    pinch.scale = 1;
}

8.拖拽手势

- (void)setUpPan{
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
    [self.imageView addGestureRecognizer:pan];
}

- (void)pan:(UIPanGestureRecognizer *)pan{
    // 移动视图
    // 获取手势的移动，也是相对于最开始的位置
    CGPoint transP = [pan translationInView:self.imageView];
    self.imageView.transform = CGAffineTransformTranslate(self.imageView.transform, transP.x, transP.y);=
    // 复位
    [pan setTranslation:CGPointZero inView:self.imageView];
}