iphone - 在ScrollView中旋转缩放ImageView？

Question

我有一个 UIScrollView ，它有一个缩放 UIImageView ，即它实现:

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

我正在尝试将 UIRotationGestureRecognizer 添加到此 imageView，具体操作如下:

_rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotate:)];
[self.imageView addGestureRecognizer:_rotationGestureRecognizer];

-(void)rotate:(id)sender
{
    UIRotationGestureRecognizer *rotationGestureRecognizer = [(UIRotationGestureRecognizer*)sender retain];

    if(rotationGestureRecognizer.state == UIGestureRecognizerStateEnded)
    {
        self.lastRotation = 0.0;
        return;
    }

    CGFloat rotation = 0.0 - (self.lastRotation - rotationGestureRecognizer.rotation);
    rotationGestureRecognizer.view.transform = CGAffineTransformRotate(rotationGestureRecognizer.view.transform, rotation);
    self.lastRotation = rotationGestureRecognizer.rotation;

    [rotationGestureRecognizer release];
}

我只是想知道，是否可以做到这一点？似乎 UIScrollView 阻止了对我的 UIImageView 的触摸，因为什么也没有发生。 Apple 是否建议不要在 UIScrollView 中使用缩放 View 来执行此操作？

Answer 1

以下代码有效。将手势添加到scrollView而不是imageView。

 UIRotationGestureRecognizer* _rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotate:)];
 [self.scrollView addGestureRecognizer:_rotationGestureRecognizer];

Swift 5 版本:

let rotationGestureRecognizer = UIRotationGestureRecognizer(target: self, action: #selector(self.rotate(_:)))
scrollView.addGestureRecognizer(rotationGestureRecognizer)