小编Bib*_*cob的帖子

当我从 Home_Fragment 按下后退按钮时，控件将转到一个空页面，当我从 Home_Fragment 按下后退按钮时，我想退出我的应用程序，同时当我从所有其他片段按下后退按钮时，我想导航到 Home_Fragment 。我的 MainActivity 页面如下。

  public class MainActivity extends ActionBarActivity implements FragmentDrawer.FragmentDrawerListener {

private static String TAG = MainActivity.class.getSimpleName();

private Toolbar mToolbar;
private FragmentDrawer drawerFragment;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mToolbar = (Toolbar) findViewById(R.id.toolbar);

    setSupportActionBar(mToolbar);
    getSupportActionBar().setDisplayShowHomeEnabled(true);

    drawerFragment = (FragmentDrawer)
            getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
    drawerFragment.setUp(R.id.fragment_navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout), mToolbar);
    drawerFragment.setDrawerListener(this);

    // display the first navigation drawer view on app launch
    displayView(0);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action …