Android Back button return previous, but exit the app

Question

Override this function, it return previous page, but at same time it will exit the app. Just press the back button once, anyone can help me solve this problem. Use V4 slide fragment.

public void onBackPressed() {
    moveTaskToBack(true);

    if (mViewPager.getCurrentItem() == 0) {
        super.onBackPressed();
    } else {

        mViewPager.setCurrentItem(mViewPager.getCurrentItem() - 1);
    }

Answer 1

moveTaskToBack(true) is the responsible for closing your app, if you only want your app to close when you are on the first page of your 'ViewPager' try moving it inside the if statement.

Something like this:

public void onBackPressed() {

    if (mViewPager.getCurrentItem() == 0) {
        moveTaskToBack(true);
    } else {
        mViewPager.setCurrentItem(mViewPager.getCurrentItem() - 1);
    }
}

Answer 2

You need use addToBackStack

public void showFragment(View v) {
FragmentA f = new FragmentA();

FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.container, f, tag);
ft.addToBackStack(tag);
ft.commit();
}

@Override
public void onBackPressed() {
    FragmentManager fm = getSupportFragmentManager();
    if (fm.getBackStackEntryCount() > 0) {
        fm.popBackStack();
    } else {
        super.onBackPressed();
    }
}

Answer 3

try this at Activity:

System.exit(1);

or at other classes you can use this:

context.System.exit(1);