【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。

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
代码：

[cpp] view
plaincopy

// 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
plaincopy

[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
plaincopy

@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
plaincopy

- (void)viewDidLoad  

{  

    [super viewDidLoad];  

  

    showImgView = [[UIImageView alloc] initWithFrame:<span class="s1">CGRectMake</span>(<span class="s2">0</span>, <span class="s2">0</span>, 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

[cpp] 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 < 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。