【IOS】使用手势对UIImageView进行缩放、旋转和移动

因为项目需要，需要对图片进行一些操作。本着拿来主义的原则~上网找了方法。

代码：

view plaincopy

//添加所有的手势

-(void)addGestureRecognizerToView:(UIView*)view

{

//旋转手势

UIRotationGestureRecognizer*rotationGestureRecognizer=[[UIRotationGestureRecognizeralloc]initWithTarget:selfaction:@selector(rotateView:)];

[viewaddGestureRecognizer:rotationGestureRecognizer];

//缩放手势

UIPinchGestureRecognizer*pinchGestureRecognizer=[[UIPinchGestureRecognizeralloc]initWithTarget:selfaction:@selector(pinchView:)];

[viewaddGestureRecognizer:pinchGestureRecognizer];

//移动手势

UIPanGestureRecognizer*panGestureRecognizer=[[UIPanGestureRecognizeralloc]initWithTarget:selfaction:@selector(panView:)];

[viewaddGestureRecognizer: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);

[rotationGestureRecognizersetRotation: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){

CGPointtranslation=[panGestureRecognizertranslationInView:view.superview];

[viewsetCenter:(CGPoint){view.center.x+translation.x,view.center.y+translation.y}];

[panGestureRecognizersetTranslation:CGPointZeroinView:view.superview];

}

}

这样只需要简单调用

view plaincopy

[selfaddGestureRecognizerToView:view];

//如果处理的是图片，别忘了

[imageViewsetUserInteractionEnabled:YES];

[imageViewsetMultipleTouchEnabled:YES];

大功告成。view plaincopy

@interfaceYourViewController:UIViewController

{

CGFloatlastScale;

CGRectoldFrame;//保存图片原来的大小

CGRectlargeFrame;//确定图片放大最大的程度

}

然后在viewDidLoad里面加上

view plaincopy

-(void)viewDidLoad

{

[superviewDidLoad];

showImgView=[[UIImageViewalloc]initWithFrame:CGRectMake(0,0,320,480)];

[showImgViewsetMultipleTouchEnabled:YES];

[showImgViewsetUserInteractionEnabled:YES];

[showImgViewsetImage:[UIImageimageNamed:@"1.jpg"]];

oldFrame=showImgView.frame;

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

[selfaddGestureRecognizerToView:showImgView];

[self.viewaddSubview: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。

我修改了缩放的代码，增加了限制，其他的类似

view plaincopy

//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 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。