ios - 如何在 iOS 的 ImageView 中添加手势识别器？

Question

我将 UIPanGestureRecognizer 添加到我的 imageview，然后添加了手势识别器，但我的 imageview 图像被平移到我的 View 中，我只想在 imageview 内部平移图像，这怎么可能？

我在 viewdidload 上写了一个代码

 UIPanGestureRecognizer *pangesture=[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panGestureDetected:)];
[pangesture setDelegate:self];
[self.zoomImage addGestureRecognizer:pangesture];

方法是

- (void)panGestureDetected:(UIPanGestureRecognizer *)recognizer
{
UIGestureRecognizerState state = [recognizer state];

if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
{
    CGPoint translation = [recognizer translationInView:recognizer.view];
    [recognizer.view setTransform:CGAffineTransformTranslate(recognizer.view.transform, translation.x, translation.y)];
    [recognizer setTranslation:CGPointZero inView:recognizer.view];
}
}

然后 imageView 图像在我的 View 中平移，但我希望图像仅在 imageview 内部平移(如果可能)然后给我解决方案。 这里我原来的 imageview 大小就像

当我添加 UIPanGEstureRecognizer 时，它看起来像
图像在 View 中平移，但我想将其缩放到 ImageView 大小内，请给我解决方案。

Answer 1

采用 UIScrollView 并在 ScrollView 内添加 UIImageView 并在 ScrollView 上添加 pangesture ..

为 ScrollView 设置委托(delegate)并执行代码

- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    // Return the view that we want to zoom
    return self.zoomImage;
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    // The scroll view has zoomed, so we need to re-center the contents
    [self centerScrollViewContents];
}

- (void)centerScrollViewContents {
    CGSize boundsSize = scrollView.bounds.size;
    CGRect contentsFrame = self.zoomImage.frame;

    if (contentsFrame.size.width < boundsSize.width) {
        contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0f;
    } else {
        contentsFrame.origin.x = 0.0f;
    }

    if (contentsFrame.size.height < boundsSize.height) {
        contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0f;
    } else {
        contentsFrame.origin.y = 0.0f;
    }

    self.zoomImage.frame = contentsFrame;
}

- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer {
    // Get the location within the image view where we tapped
    CGPoint pointInView = [recognizer locationInView:imageView];

    // Get a zoom scale that's zoomed in slightly, capped at the maximum zoom scale specified by the scroll view
    CGFloat newZoomScale = scrollView.zoomScale * 1.5f;
    newZoomScale = MIN(newZoomScale, scrollView.maximumZoomScale);

    // Figure out the rect we want to zoom to, then zoom to it
    CGSize scrollViewSize = scrollView.bounds.size;

    CGFloat w = scrollViewSize.width / newZoomScale;
    CGFloat h = scrollViewSize.height / newZoomScale;
    CGFloat x = pointInView.x - (w / 2.0f);
    CGFloat y = pointInView.y - (h / 2.0f);

    CGRect rectToZoomTo = CGRectMake(x, y, w, h);

    [scrollView zoomToRect:rectToZoomTo animated:YES];
}

- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer {
    // Zoom out slightly, capping at the minimum zoom scale specified by the scroll view
    CGFloat newZoomScale = scrollView.zoomScale / 1.5f;
    newZoomScale = MAX(newZoomScale, scrollView.minimumZoomScale);
    [scrollView setZoomScale:newZoomScale animated:YES];
}