同步放大两个UIScrollViews。

Question

我有两个UIScrollViews。这两个滚动视图都包含一个图像。现在，我想以编程方式缩放第二个滚动视图，如果我手动放大第一个滚动视图。我正在使用 - （UIView *）viewForZoomingInScrollView：（UIScrollView *）scrollView方法手动缩放第一个滚动视图。第二个滚动视图应放大到相同的点和缩放比例。我怎样才能做到这一点？

Answer 1

尝试像这样在UIScrollViewDelegate方法：

override func scrollViewDidScroll(scrollView: UIScrollView){ 
    otherScrollView.contentOffset = scrollView.contentOffset 
    otherScrollView.zoomScale = scrollView.contentOffset 
} 

Answer 2

通过使用这两个scrollviews的标签或物体可以识别哪些滚动查看您需要放大viewForZoomingInScrollView方法。

e.g

//need to set the tag for scrollviews 
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView 
{ 
if(scrollView.tag == 1) 
{ 
    return firstImageView; 
} 
return secondImageView; 

} 

OR 

//need to create the object of used scrollviews 
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView 
{ 
if(scrollView == objScrollViewFirst) 

{ 
    return firstImageView; 
} 
return secondImageView; 

} 

Answer 3

怎么是这样的：

CGRect zoomRect; 
zoomRect.size.height = manualScrollView.frame.size.height/manualScrollView.zoomScale; 
zoomRect.size.width = manualScrollView.frame.size.width/manualScrollView.zoomScale; 
zoomRect.origin.x = manualScrollView.center.x - (zoomRect.size.width/2.0); 
zoomRect.origin.y = manualScrollView.center.y - (zoomRect.size.height/2.0); 

[autoScrollView zoomToRect:zoomRect animated:YES]; 
[autoScrollView setZoomScale:manualScrollView.zoomScale animated:YES];