触摸事件 手势

当一个或多个手指触碰屏幕时
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
当一个或多个手指在屏幕上移动时
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
当一个或多个手指离开屏幕时
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
当触摸事件被打断时（如来电话了，取消触摸事件时）
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    //--------------------单击、双击----------------------
    UITouch *touch = [touches anyObject];//touches里相当于有几个手指触摸
    NSUInteger tapCount = touch.tapCount;//触摸的次数
    if (tapCount == 1) {//如果单机
        [self performSelector:@selector(singleTap) withObject:nil afterDelay:0.5];// 0.5秒以后执行
    }
    else if(tapCount == 2) {
        [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(singleTap) object:nil];// 取消执行单机
        [self doubleTap];
    }
    CGPoint point = [touch locationInView:self];//获取手指在当前view上的坐标
}

当用户触摸屏幕时，事件会被封装成一个event实例，包含了触摸的相关信息（位置信息），event实例中包含着若干个UITouch信息，一个touch相当于一个手指，touchs的数量

相当于用户手指的数量；

UITouch的常用属性：

window:触摸产生时所在的窗口
view:触摸产生时所在的view
tapCount:短时间内点击的次数，可以用于判断单击和双击
timestamp:触摸事件产生或变化的时间，单位为秒
phase:触摸事件在触摸周期中所处的状态：包括：
    UITouchPhaseBegan,             // 开始触摸.
    UITouchPhaseMoved,             // 触摸点移动
    UITouchPhaseStationary,        // 触摸点无移动
    UITouchPhaseEnded,             // 触摸结束
    UITouchPhaseCancelled,        // 触摸取消

UITouch常用方法：

    CGPoint point = [touch locationInView:self];//获取这次触摸的坐标点
    CGPoint point2 = [touch previousLocationInView:self];//获取上一个触摸的坐标点

捏合事件：

要实现多点触摸必须使此属性为yes

//开启多点触摸
self.multipleTouchEnabled = YES;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    if ([touches count] == 2) {
        NSArray *touchArray = [touches allObjects]; //获取触摸点个数
        UITouch *firstTouch = [touchArray objectAtIndex:0]; //取出第一个触摸点
        UITouch *secondTouch = [touchArray objectAtIndex:1]; //取出第二个触摸点
//        secondTouch.tapCount;//获取点击次数

        CGPoint point1 = [firstTouch locationInView:self];//获取第一个触摸点所在的位置
        CGPoint point2 = [secondTouch locationInView:self];;//获取第二个触摸点所在的位置
 
        double distance = [self distance:point1 point:point2];//计算两点间的距离
        NSLog(@"%f",distance);
    }
}
//计算两点之间的距离
- (double)distance:(CGPoint)p1 point:(CGPoint)p2 {
    // ((x1-x2)平方+(y1-y2)平方)开方
    double distnce = sqrt(pow(p1.x-p2.x, 2)+pow(p1.y-p2.y, 2));
    return distnce;
}

事件响应者链

UIApplication   UIView   UIWindow  UIViewController都使直接或间接继承UIResponser,所以这些类的实例都是响应者对象

响应者链表示一系列的响应者对象。事件由UIApplication->UIWindow->...->第一响应者（被直接点击的对象），事件将由第一响应者来处理，如果

第一相应着处理不了，或第一相应者不处理，将交给下一个响应者（它的父视图）来处理，最后传到UIApplication，如果不处理，事件丢弃；

手势识别器

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    //----------------------点击手势-------------------------
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)];
    [self.view addGestureRecognizer:tap];
    
    UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doubleTap:)];
    doubleTap.numberOfTapsRequired = 2;
    [self.view addGestureRecognizer:doubleTap];
    
    //区别单击、双击手势
    [tap requireGestureRecognizerToFail:doubleTap];
    
    //----------------------轻扫手势-------------------------
    UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeAction:)];
    swipeGesture.direction = UISwipeGestureRecognizerDirectionUp;
    [self.view addGestureRecognizer:swipeGesture];
    
    //----------------------滑动手势-------------------------
    UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panAction:)];
    [self.view addGestureRecognizer:panGesture];

    //----------------------长按手势-------------------------
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressAction:)];
    longPress.minimumPressDuration = 2;
    [self.view addGestureRecognizer:longPress];
    
    //----------------------旋转手势-------------------------
    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationAction:)];
    [self.view addGestureRecognizer:rotation];
    
    //----------------------捏合手势-------------------------
    UIPinchGestureRecognizer  *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchAction:)];
    [self.view addGestureRecognizer:pinch];
}

- (void)tap:(UITapGestureRecognizer *)tapGetrue {
    NSLog(@"单击");
}

- (void)doubleTap:(UITapGestureRecognizer *)tapGetrue {
    NSLog(@"双击");
}

- (void)swipeAction:(UISwipeGestureRecognizer *)swipeGesture {
    NSLog(@"轻扫");
}

- (void)longPressAction:(UILongPressGestureRecognizer *)longPress {
    if (longPress.state == UIGestureRecognizerStateEnded) {
        return;
    }
    NSLog(@"长按");
    
    
}

- (void)panAction:(UIPanGestureRecognizer *)panGesture {
    CGPoint p = [panGesture locationInView:self.view];
    NSLog(@"%@",NSStringFromCGPoint(p));
}

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

    //角度
    float degree = rotation.rotation*(180/M_PI);
    
    NSLog(@"%f",degree);
    
}

- (void)pinchAction:(UIPinchGestureRecognizer *)pinch {
    if (pinch.scale > 0) {
        NSLog(@"放大");
    } else {
        NSLog(@"缩小");
    }
    NSLog(@"%f",pinch.scale);
}

滑动手势

    CGPoint translatedPoint = [panGesture translationInView:self.view];

    

    NSLog(@"%f",translatedPoint.x);

translatedPoint.x小于0向做滑动，大于0向右滑动