iphone - UIPinchGestureRecognizer 和 UIImageView 的问题

Question

我正在尝试通过 UIPinchGestureRecognizer 捏图像，但是问题是我的代码无法正常工作，实际上它无法缩放我的图像

-(void) pinching: (UIPinchGestureRecognizer *) sender {

    CGAffineTransform myTransformation =
    CGAffineTransformMakeScale(sender.scale, sender.scale);
    sender.view.transform = myTransformation;
}


- (void)viewDidLoad
{
  UIPinchGestureRecognizer *pinch =
    [[UIPinchGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(pinching:)];

    pinch.delegate = self;

    [imageBG addGestureRecognizer:pinch];

    [imageBG setUserInteractionEnabled:YES];
    [imageBG setMultipleTouchEnabled:YES];
}

Answer 1

尝试使用UIScrollView。

为此，请创建它

self.scrollView = [[UIScrollView alloc] initWithFrame:...];
self.scrollView.delegate = self;
self.scrollView.maximumZoomScale = 2.0; // adjust as you need
self.scrollView.minimumZoomScale = 0.5; // adjust as you need
[self.scrollView addSubview:self.imageView];

并添加委托(delegate)方法:

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return self.imageView;
}