组成部分
- Model：数据，业务逻辑
- View：显示，UI
- ViewModel：绑定前两者
工作流程
传统MVC模式中，controller把model推到view中，而在MVVM中，ViewModel改变Model的内容后，framework将负责把变化更新到View中；Model和View通过ViewModel的接口若耦合；
得益于此，MVVM的测试不依赖于View的存在，只需注入相应依赖即可；测试model时，检查ViewModel的对应方法是否被调用；测试View时，使用mock Model，检查View内容的显示正确性；
To reads(When stable released/decide to use)
- https://developer.android.com/tools/data-binding/guide.html
- http://stablekernel.com/blog/mvvm-on-android-using-the-data-binding-library
- https://medium.com/@fabioCollini/android-data-binding-f9f9d3afc761
- https://blog.stylingandroid.com/data-binding-part-1/
- https://realm.io/news/data-binding-android-boyar-mount/
- https://medium.com/ribot-labs/approaching-android-with-mvvm-8ceec02d5442
- https://github.com/LyndonChin/MasteringAndroidDataBinding/blob/master/README.md
- Android Data Binding 1.0-rc4 is now available and fixes the issues with gradle plugin 1.4-beta6