iOS中的手势

       因为手势识别，所以爱上了苹果的。对我而言确实如此。在MBP上用触控板完全操控它，感觉爽极了，两点右击，三点拖动等等。后来换成Mac Mini很不适应。

在iOS中也有很多手势，如拖动，滑动，旋转，点击，长按，缩放等等。iOS中添加手势识别步骤基本如下：

• 定义手势
• 绑定事件
• 将手势添加到对象上
• 在绑定事件上

先创建一个空的工程，接着创建一个ViewController,为其添加一个属性：UIImageView *_imageView。我们所以的手势都暂时在这个UIImageView上演示，因为它的userInteractionEnabled属性默认是NO，所以先要设置为YES。

 _imageView.userInteractionEnabled = YES;

手势代码如下：

    //手势
    //轻触手势
    UITapGestureRecognizer* tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)];
    //点击次数
    tap.numberOfTapsRequired = 2;
    tap.numberOfTouchesRequired = 2;
    //[_imageView addGestureRecognizer:tap];
    //长按手势
    UILongPressGestureRecognizer* longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
    //[_imageView addGestureRecognizer:longPress];
    
    //移动
    UIPanGestureRecognizer* pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
    //[_imageView addGestureRecognizer:pan];
    
    //旋转
    UIRotationGestureRecognizer* rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)];
    //[_imageView addGestureRecognizer:rotation];
    
    //捏合
    UIPinchGestureRecognizer* pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)];
    //[_imageView addGestureRecognizer:pinch];
    
    UISwipeGestureRecognizer* swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)];
    //右边方向
    swipe.direction = UISwipeGestureRecognizerDirectionLeft;
    [_imageView addGestureRecognizer:swipe];
    
    UISwipeGestureRecognizer* swipe2 = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)];
    //左边方向
    swipe2.direction = UISwipeGestureRecognizerDirectionRight;
    [_imageView addGestureRecognizer:swipe2];
}

- (void)swipe:(UISwipeGestureRecognizer*)swipe
{
    if (swipe.direction == UISwipeGestureRecognizerDirectionLeft)
    {
        NSLog(@"向左边滑");
    }
    if (swipe.direction == UISwipeGestureRecognizerDirectionRight)
    {
        NSLog(@"向右边滑");
    }
}

- (void)pinch:(UIPinchGestureRecognizer*)pinch
{
    _imageView.bounds = CGRectMake(0, 0, _imageView.bounds.size.width * pinch.scale, _imageView.bounds.size.height * pinch.scale);
    [pinch setScale:1];
}

- (void)rotation:(UIRotationGestureRecognizer*)rotation
{
    _imageView.transform = CGAffineTransformRotate(_imageView.transform, rotation.rotation);
    [rotation setRotation:0];
}

//移动
- (void)pan:(UIPanGestureRecognizer*)pan
{
    CGPoint point = [pan translationInView:self.view];
    NSLog(@"%@",NSStringFromCGPoint(point));
    _imageView.center = CGPointMake(_imageView.center.x + point.x, _imageView.center.y + point.y);
    //偏移量设置为0
    [pan setTranslation:CGPointZero inView:self.view];
    /*
     x: 0  1  1  1
     y: 0  1  0  0
     
     0,0 1,1 3,2 6,3
     
     */
}

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

//轻触
- (void)tap:(UITapGestureRecognizer*)tap
{
    NSLog(@"轻触");
}

                  
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    //NSLog(@"touchesBegan");
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    UITouch* touch = [touches anyObject];
    CGPoint point = [touch locationInView:self.view];
    //NSLog(@"%f, %f", point.x, point.y);
    //1,1 2,1  1,0
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
    //NSLog(@"touchesEnded");
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{
    //NSLog(@"touchesCancelled");
}