How to control hardware back button [closed]

Answer 1

Try this:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) 
{
    if(keyCode == KeyEvent.KEYCODE_BACK)
    {
        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_HOME);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
        return true;
    }
return false;
}

Answer 2

You will have to store the instances of all 5 Activities in a common class, and add an onBackPressed() in every activity, which will call a method in the common class which will call activity.finish() on each of the 5 Activities.

For example:

class Activity1 extends Activity {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        MyController.getInstance().setActivity1(this);
    }

    public void onBackPressed() {
        MyController.getInstance().closeAllActivities();
        super.onBackPressed();
    }
}

Similarly, write for Activity2, Activity3, and so on. And, MyController class would look like this:

class MyController {
    private static MyController instance;
    private Activity activity1, activity2, activity3, activity4, activity5;

    private MyController() {}
    public static synchronized MyController getInstance() {
        if(instance == null) {
            instance = new MyController;
        }

        return instance;
    }

    public void setActivity1(Activity activityObject) { activity1 = activityObject; }
    public void setActivity2(Activity activityObject) { activity2 = activityObject; }
    public void setActivity3(Activity activityObject) { activity3 = activityObject; }
    public void setActivity4(Activity activityObject) { activity4 = activityObject; }
    public void setActivity5(Activity activityObject) { activity5 = activityObject; }

    public void closeAllActivities() {
        if(activity1 != null) {
            activity1.finish();
        }
        if(activity2 != null) {
            activity2.finish();
        }
        if(activity3 != null) {
            activity3.finish();
        }
        if(activity4 != null) {
            activity4.finish();
        }
        if(activity5 != null) {
            activity5.finish();
        }
    }
}