Android rewrite the difference between view and ViewGroup

Rewrite view:

The view class is generally used for drawing operations, overriding its OnDraw method, but it can not contain other components, and there is no AddView (view view) method.

Rewrite viewgroup:

ViewGroup is a component container that can contain any component, but must override OnLayout (Boolean changed,int l,int t,int r,int B) and onmesure (int widthmesurespec,int Heightmesurespec) method. Otherwise, the add component in ViewGroup is not displayed.

Custom rewrite linearlayout:

There seems to be no need to rewrite the OnLayout method, because LinearLayout itself is inherited from ViewGroup but the constructor will appear to add @SuppressLint ("Newapi")

-----to be continued to improve

Android rewrite the difference between view and ViewGroup