[How to set the image to a specific point in the zoom? ? ?

Using CGAffineTransformScale, the default is the center point of View to zoom.
But after scaling the position is not what I want.
Now I want it to the midpoint of the two finger zoom to the center, how to set? ?
I set up View.layer.anchorPoint, but the picture was gone when zooming, I do not know where to go to be moved to a ...
Reply:
Why not UIScrollView it?
On one line of code to get.
Better results.
Reply:

cited a floor ybh37 reply:

Why not UIScrollView it?
On one line of code to get.
Better results.

I really zooming UIScrollView in the picture, but how UIScrollView in pictures, but also because there while rotating the zoom gesture, the angle of rotation will be retained after the hand release
The viewForZoomingInScrollView with UIScrollView does not seem to do ...