使用手势对UIImageView进行缩放旋转和移动
Posted Sinner_Yun
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- // 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
- [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
- @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
- - (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
- // 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
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