3-Layer Geometry

Frame

    frame实际上代表了覆盖在图层旋转之后的整个轴对齐的矩形区域,也就是说,frame的宽高可能和    bounds的宽高不再一致        frame是一个虚拟属性,是根据bounds,position 和 transfrom计算而来    

Archorpoint

Both the Center property of the view and the position property of the layer specify the position of the anchorpoint relative to the parent layer

By default, the Anchorpoint is in the focus of the layer, so the layer will be centered on this point to place

TODO: Complete this demo

Learn about the coordinate system used by iOS

Coordinates

    UIView 是一个严格的二维坐标系,CALayer则存在三位坐标,CALayer还有zPosition、anchorPointZ坐标        zPosition除了在三位动画的时候有用,其最实用的功能是改变图层的显示顺序    layer.zPositon = 1.0f; 即可(图层非常薄,设置为0.01都可以)

3-Layer Geometry