【Android】Error: Suspicious namespace and prefix combination [NamespaceTypo] when I try create Signed APK

ref:
https://stackoverflow.com/a/34165565

change the code xmlns:app="http://schemas.android.com/tools" with this:

xmlns:app="http://schemas.android.com/apk/res-auto"

It made mine work.

【Android】ToolBar的title居中以及一些注意事项

ref:
http://blog.csdn.net/picasso_l/article/details/50159095