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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];

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;    }}

这样就保证了图片的最大和最小比例。

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