build.gradlefile of your project:
loginIn()function must be called in your
LoginActivityjust after user login success to your application. It allows to save the user id in a file and therefore you d'ont need to login the user each time you launch application.
loginIn()function can be executed offline and the saved user id can only be cleared by executing
userIdis the primary field value of your users table in application database.
FrameLayoutcomponent to MainActivity layout activity_layout.xml.
oncreate()method of your main activity, affect