使用手势对UIImageView进行缩放、旋转和移动

时间：2017-08-10 13:36:38 阅读：331 评论：0 收藏：0 [点我收藏+]

标签：show details multiple 代码 ref interface use gpo img

[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:CGRectMake(0, 0, 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

使用手势对UIImageView进行缩放、旋转和移动

标签：show details multiple 代码 ref interface use gpo img

原文地址：http://www.cnblogs.com/-yun/p/7338422.html

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