保存状态导航抽屉页面（片段）

Question

I've had a search on SO and can't find anything that works.

Here's what I want to do, when I navigate between navigation drawer pages, I want the view to be the same. So if I go from page A to B, and then from B to A. I expect A to have the same state.

In my app, I add some text to fragment A via some button. When I navigate to fragment B, and then back to A, the text is gone. I want the text to still be there.

How do I do this?

I've already tried setRetainState(true). This doesn't work. I have also made sure that new Fragment() is only called once when going to the page. This also doesn't work.

The structure of my navigation drawer is identical to the one shown in the Android documentation.

Answer 1

I think, if you have a navigation drawer that you use fragments for each page. On select item in navigation drawer don't recreate the fragment, just pop it from back stack if it exists.

 HomeFragment homeFragment = (HomeFragment) fm.findFragmentByTag(fragmentName);
 if (homeFragment == null) {
     homeFragment = new HomeFragment();
     fm.beginTransaction().addToBackStack(fragmentName).replace(R.id.content_frame, homeFragment, fragmentName).commit();
 } else {
      fm.popBackStackImmediate(fragmentName, 0);
 }