【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。