How can I maintain state when switching between action bar tabs / fragments?

Question

I have a number of fragments attached to the Android action bar as tabs. I can switch between them without problems. However, if one of the fragments has a TextView (for example), and I alter the text of that TextView, the new text is not kept if I switch to another tab and back.

I've tried overriding onSaveInstanceState(), but it appears it is not called when I switch tabs, as savedInstanceState is null every time onActivityCreated() is called (i.e. every time that tab is reopened).

I looked into altering onPause() such that it calls onSaveInstanceState(), but onPause() doesn't have access to the state bundle, so I don't see how I can do that.

What is the best way to keep state in a tab when going back and forth between tabs?

Answer 1

When you are switching between fragments, don't detach fragments just hide. Example:

@Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
      FragmentManager fm = getFragmentManager(); 
      if(fm.findFragmentByTag(tab.getTag().toString()) == null){
           ft = fm.beginTransaction();
           FragmentContent contentfrag = new FragmentContent();
           ft.add(R.id.framelayout, contentfrag, tab.getTag().toString());
           ft.addToBackStack("BackStack" + tab.getTag().toString());
       }
       else{
           Fragment frag = fm.findFragmentByTag(tab.getTag().toString());
           ft.show(frag);
      }
}

    @Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        Fragment frag = this.getFragmentManager().findFragmentByTag(tab.getTag().toString());
    ft.hide(frag);

}