iOS Core animation work notes

1. The difference between layers and UIView: layers cannot interact with users, and a picture with a high layer performance of 2.imageVIew is shown as a sublayer above the layer. Cut with Maskbounds is a layer, the user can not see is because the sub-layer block 3. Calayer Proxy method does not have a protocol, any object can become his agent, that is, NSObject method 4.UIVIew internal root layer of the proxy is the view itself, so in UIView DrawRect method drawing. A view cannot set the proxy. Because it is already a proxy for its layer 5. The Core animation directly acts on the Calayer, and the downside is that the real frame of the picture after the animation has not changed. The rotation of the 6.transfrom revolves around the anchor point.