I am working on this Android Studio project, and after I'm making some checks in the Login activity, I want to be redirected to the MainActivity and finish the Login activity. However, after I login and I am being redirected to the MainActivity, if I press the back button, it will redirect me back to the Login Activity(the first time the login activity not being closed/finished). If I try to repeat the process and press back, this time works as desired, that is, it closes the app(the Login activity is closed/finished) I checked my code a few times now, and I am not starting the same activity twice, so does anybody know why this happens and how to fix it?
Try to use finishAffinity() which closes the current activity and clears the stack. Then you will be left with MainActivity only.
More information: https://developer.android.com/reference/android/app/Activity#finishAffinity()