更新时间:2022-11-02 10:03:26
示例代码:
- (void)handleTwoFingerTap:(UIGestureRecognizer *)gestureRecognizer
{
// two-finger tap zooms out
float newScale = [scrlView zoomScale] / ZOOM_STEP;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[scrlView zoomToRect:zoomRect animated:YES];
}
- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center
{
CGRect zoomRect;
// the zoom rect is in the content view's coordinates.
// At a zoom scale of 1.0, it would be the size of the imageScrollView's bounds.
// As the zoom scale decreases, so more content is visible, the size of the rect grows.
zoomRect.size.height = [scrlView frame].size.height / scale;
zoomRect.size.width = [scrlView frame].size.width / scale;
// choose an origin so as to get the right center.
zoomRect.origin.x = scrlView.center.x - (zoomRect.size.width / 2.0);
zoomRect.origin.y = scrlView.center.y - (zoomRect.size.height / 2.0);
return zoomRect;
}