如何根据旋转原点旋转视图，在视图坐标系中指定谁的位置？

I find this pretty confusing. When you want to rotate a view, it's going to be rotated by it's center point. But that's not always good. So if you need to rotate by an specified origin in your view, you would have to set the anchorPoint property of the view's layer. I find this pretty confusing. When you want to