使用手势对UIImageView进行缩放、旋转和移动

[cpp] view plain copy

// 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];

}

}

这样只需要简单调用

[cpp] view plain copy

[self addGestureRecognizerToView:view];

//如果处理的是图片，别忘了

[imageView setUserInteractionEnabled:YES];

[imageView setMultipleTouchEnabled:YES];

大功告成。

具体使用一下：

在.h文件里边定义变量

[cpp] view plain copy

@interface YourViewController : UIViewController<UIGestureRecognizerDelegate>

{

CGFloat lastScale;

CGRect oldFrame; //保存图片原来的大小

CGRect largeFrame; //确定图片放大最大的程度

}

然后在viewDidLoad里面加上

[cpp] view plain copy

- (void)viewDidLoad

{

[super viewDidLoad];

showImgView = [[UIImageView alloc] initWithFrame:<span class="s1">CGRectMake</span>(<span class="s2">0</span>, <span class="s2">0</span>, 320, 480)];

[showImgView setMultipleTouchEnabled:YES];

[showImgView setUserInteractionEnabled:YES];

[showImgView setImage:[UIImage imageNamed:@"1.jpg"]];

oldFrame = showImgView.frame;

largeFrame = CGRectMake(0 - screenSize.width, 0 - screenSize.height, 3 * oldFrame.size.width, 3 * oldFrame.size.height);

[self addGestureRecognizerToView:showImgView];

[self.view addSubview:showImgView];

这样就实现了

但是，这样是不够的。

因为里边的缩放和移动等没有做相应的判断。

因为代码很简洁，所以扩展也非常方便。

修改了缩放的代码，增加了限制，其他的类似

[cpp] view plain copy

// 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);

if (showImgView.frame.size.width < oldFrame.size.width) {

showImgView.frame = oldFrame;

//让图片无法缩得比原图小

}

if (showImgView.frame.size.width > 3 * oldFrame.size.width) {

showImgView.frame = largeFrame;

}

pinchGestureRecognizer.scale = 1;

}

}

这样就好了。保证了图片的最大和最小比例。

参考文章： http://apluck.iteye.com/blog/1781607