七大手势

在设置手势之前一定要将用户交互打开

self.userInteractionEnabled = YES;

若是在做相册的话 设置捏合以及旋转手势之后 想让其在切换之后恢复原样 要抓住切换图片这个时机 切换图片设置的时候一般是轻扫和轻拍 要设置一个属性用来记录初始时候的transform

CGAffineTransform _transform;

之后将初始的相框属性赋值个给他

_transform = self . imageView . transform ;

在切换图片的时候即在轻拍事件和轻扫事件中

 tap. view . transform = _transform ;

tap.view代表当前轻拍的那个图片

轻拍手势
  1.创建手势对象
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAction:)];
  2.配置手势属性
    设置轻拍的次数
    tap.numberOfTapsRequired = 1;
    设置轻拍时手指的个数
    tap.numberOfTouchesRequired = 2;  
  3.将手势添加到指定视图上
    [_imageView addGestureRecognizer:tap];
  4.移除手势
    [_imageView removeGestureRecognizer:tap];
  设置手势之后一定要记得去实现其事件
 
轻拍事件
- (void)tapAction:(UITapGestureRecognizer *)tap
{
    改变图片
    if (_isFirst ) {
        _imageView.image = [UIImage imageNamed:@"2.JPG"];
        _isFirst = NO;
    }else{
        _imageView.image = [UIImage imageNamed:@"3.JPG"];
        _isFirst = YES;
}


平移手势
    1.创建对象
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panAction:)];
   添加到指定视图
    [_imageView addGestureRecognizer:pan];
    移除手势
    [_imageView removeGestureRecognizer:pan];
    
平移事件
- (void)panAction:(UIPanGestureRecognizer *)pan
{
    获取手势在视图上的位置
    CGPoint position = [pan translationInView:_imageView];
    进行平移  transform
    _imageView.transform = CGAffineTransformTranslate(_imageView.transform, position.x, position.y); 
    将增量置为0
    [pan setTranslation:CGPointZero inView:_imageView]; 
}
    

轻扫手势
    1.创建对象
    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeAction:)]; 
    设置轻扫方向
    对于一个轻扫手势方向只能设置一对,要么上下,要么左右 如果想都设置,需要再创建一个轻扫手势
    swipe.direction = UISwipeGestureRecognizerDirectionRight | UISwipeGestureRecognizerDirectionLeft;
    swipe.direction = UISwipeGestureRecognizerDirectionDown | UISwipeGestureRecognizerDirectionUp;
    添加到指定视图
    [_imageView addGestureRecognizer:swipe];
    移除手势
    [_imageView removeGestureRecognizer:swipe];
    
轻扫事件
- (void)swipeAction:(UISwipeGestureRecognizer *)swipe
{
    改变图片
    if (_isFirst ) {
        _imageView.image = [UIImage imageNamed:@"2.JPG"];
        _isFirst = NO;
    }else{
        _imageView.image = [UIImage imageNamed:@"3.JPG"];
        _isFirst = YES;
    }
}


长按手势
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressAction:)];
    //配置属性
    //设置最短长按时间
    longPress.minimumPressDuration = 1;
    //设置允许移动的最大距离
    longPress.allowableMovement = 10;
    //添加指定视图
    [_imageView addGestureRecognizer:longPress];
    
长按事件
- (void)longPressAction:(UILongPressGestureRecognizer *)longPress
{
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:@"是否要保存图片" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确认", nil];

    当长按开始的时候弹出提示框
    if (longPress.state == UIGestureRecognizerStateBegan) {
        [alertView show];
    }
   
    保存图片 保存到手机相册
    UIImageWriteToSavedPhotosAlbum(UIImage *image, id completionTarget, SEL completionSelector, void *contextInfo)
}


旋转手势
    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationAction:)];
   
    //添加到指定视图
    [_imageView addGestureRecognizer:rotation];
   
    //移除手势
    [_imageView removeGestureRecognizer:rotation];
    
旋转事件
- (void)rotationAction:(UIRotationGestureRecognizer *)rotation
{
    通过仿射变换 让视图旋转
    _imageView.transform = CGAffineTransformRotate(_imageView.transform, rotation.rotation); 
    将旋转角度置为0
    rotation.rotation = 0;
}


捏合手势
    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchAction:)];
   
    //添加指定视图
    [_imageView addGestureRecognizer:pinch];
   
    //移除手势
    [_imageView removeGestureRecognizer:pinch];
    
//捏合事件
- (void)pinchAction:(UIPinchGestureRecognizer *)pinch
{
    //通过transform 进行捏合
    _imageView.transform = CGAffineTransformScale(_imageView.transform, pinch.scale, pinch.scale);
    pinch.scale = 1;
}


屏幕边缘手势
    UIScreenEdgePanGestureRecognizer *screenPan = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:@selector(screenPanAction:)];
   
    设置边缘方向
    screenPan.edges = UIRectEdgeRight;
   
    添加到指定视图
    [_imageView addGestureRecognizer:screenPan];
   
}

屏幕边缘事件
- (void)screenPanAction:(UIScreenEdgePanGestureRecognizer *)screenPan
{
    NSLog(@"边缘手势触发了");
}