Understanding the Issue: Finishing Activities in Android

To ensure a smooth user logout process, it is essential to finish all previous activities when the logout button is clicked. This prevents lingering screens from interfering with the login procedure. Despite repeated attempts using FLAG_ACTIVITY flags, the issue persists in Android 1.6, which lacks support for FLAG_ACTIVITY_CLEAR_TASK.

Solution: Employing FLAG_ACTIVITY_CLEAR_TOP

The recommended solution is to utilize the FLAG_ACTIVITY_CLEAR_TOP flag. By incorporating it into the Intent, you can clear all activities stacked above the specified target activity:

Intent intent = new Intent(getApplicationContext(), Home.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

This code snippet initializes an Intent with a target activity (Home) and sets the FLAG_ACTIVITY_CLEAR_TOP flag. Upon starting this Intent, all activities above Home will be cleared, ensuring a clean transition.

Additional Considerations

If desired, you can add an extra parameter to the Intent. This extra can be retrieved in the Home activity and used to finish it as well, thereby prompting the launch of the login screen. Alternatively, you could set the login activity as the target of the Intent, potentially clearing activities below the current screen location. However, the ordering of activities in this scenario is subject to Android's specific behavior.