only importing the design library jar file is not enough. You need to import resource of android-design-library project while the jar file only contains class files.
Do as I say:
- import android-design-library project. The project is at
“sdk/extras/android/support/design/“. And set it as a library
project if it is not. - import the above project into your main project as a library.
You have to do this, because xmlns:app="http://schemas.android.com/apk/res-auto" means your need local resources from your library project or the current project, in this case, it means you need resources from the library project of android-design-library.