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。但是发现网上很多实现，要么过于复杂，要么不够完善。终于找到一篇比较好的文章。
参考文章： http://apluck.iteye.com/blog/1781607
// 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
{
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: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。我修改了缩放的代码，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。