Android保存后退片段历史记录

Question

I put in backstack fragments: A->B->C->D, where A is starting fragment for activity. After pressed home button, use other apps and return in my app, activity restarted and i see fragment A. How can i save all history of backstack?

code example for addbackstack:

FragmentManager fragmentManager = getFragmentManager();
    fragmentManager.beginTransaction().addToBackStack(null)                .setCustomAnimations(R.animator.slide_in_left,R.animator.slide_out_right,0,0)
            .replace(R.id.container, new SettingsContentFragment(item))
            .commit();

if it can help - i use NavigationDrawerFragment, part of my onCreate in activity:

    super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
        saveToolbar = (Toolbar) findViewById(R.id.toolbar);
        if (saveToolbar != null) {
            setSupportActionBar(saveToolbar);
        }
        saveToolbar.setNavigationIcon(R.drawable.ic_ab_drawer);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);



        mNavigationDrawerFragment = (NavigationDrawerFragment)


getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
    mNavigationDrawerFragment.customSetArguments(items);
    mTitle = getTitle();
    mNavigationDrawerFragment.setUp(
        R.id.navigation_drawer,
        (DrawerLayout) findViewById(R.id.drawer_layout));

Answer 1

You call addToBackStack(null) method before you perform a transaction. As a result nothing is actually added to back stack. Try

fragmentManager.beginTransaction()
 .setCustomAnimations(R.animator.slide_in_left,R.animator.slide_out_right,0,0)
  .replace(R.id.container, new SettingsContentFragment(item))
  .addToBackStack(null)
  .commit();

instead