使用手势对UIImageView进行缩放、旋转和移动

// 添加所有的手势  
- (void) addGestureRecognizerToView:(UIView *)view  
{  
    // 旋转手势  
    UIRotationGestureRecognizer *rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotateView:)];  
    [view addGestureRecognizer:rotationGestureRecognizer];  
    // 缩放手势  
    UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchView:)];  
    [view addGestureRecognizer:pinchGestureRecognizer];  
    // 移动手势  
    UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panView:)];  
    [view addGestureRecognizer:panGestureRecognizer];  
}  
// 处理旋转手势  
- (void) rotateView:(UIRotationGestureRecognizer *)rotationGestureRecognizer  
{  
    UIView *view = rotationGestureRecognizer.view;  
    if (rotationGestureRecognizer.state == UIGestureRecognizerStateBegan || rotationGestureRecognizer.state == UIGestureRecognizerStateChanged) {  
        view.transform = CGAffineTransformRotate(view.transform, rotationGestureRecognizer.rotation);  
        [rotationGestureRecognizer setRotation:0];  
    }  
}  
// 处理缩放手势  
- (void) pinchView:(UIPinchGestureRecognizer *)pinchGestureRecognizer  
{  
    UIView *view = pinchGestureRecognizer.view;  
    if (pinchGestureRecognizer.state == UIGestureRecognizerStateBegan || pinchGestureRecognizer.state == UIGestureRecognizerStateChanged) {  
        view.transform = CGAffineTransformScale(view.transform, pinchGestureRecognizer.scale, pinchGestureRecognizer.scale);  
        pinchGestureRecognizer.scale = 1;  
    }  
}  
// 处理拖拉手势  
- (void) panView:(UIPanGestureRecognizer *)panGestureRecognizer  
{  
    UIView *view = panGestureRecognizer.view;  
    if (panGestureRecognizer.state == UIGestureRecognizerStateBegan || panGestureRecognizer.state == UIGestureRecognizerStateChanged) {  
        CGPoint translation = [panGestureRecognizer translationInView:view.superview];  
        [view setCenter:(CGPoint){view.center.x + translation.x, view.center.y + translation.y}];  
        [panGestureRecognizer setTranslation:CGPointZero inView:view.superview];  
    }  
}  

[self addGestureRecognizerToView:view];    
//如果处理的是图片，别忘了  
[imageView setUserInteractionEnabled:YES];    
[imageView setMultipleTouchEnabled:YES];