Databinding 請使用android-studio 3.1 up... (不要問為啥,你會怕)

記得有雙向binding @={.....}

for obj class. extends BaseObservable implements Serializable （Serializable for bundle at intent等等）

  obj   method  , @Bindable

use in viewmodes/ ObservableField<YourObject> ...;

viewmodel 溝通其他viewmodel (透過activity訂閱, 想再寫個mvp也可假設邏輯很複雜的話)

In viewmodel -> 1. extends Observable

1. setChanged(); notifyObservers(); 通知訂閱者(activity)

   In 訂閱者(activity) :

   1. implement Observer
   2. model.addObserver(this) .....

寫到最後其實不怎用databinding....來不及一直改spec 還沒習慣databinding code style

不過drawlayout 共用下來真的還不錯