How to pop fragment off backstack

Question

I have an activity A, which calls fragment Bf, which calls fragment Cf. I want Bf to be placed in the backstack when Cf is called so that users can navigate back to it. However, if a specific button is pressed in Cf, I would like Bf to be removed from the backstack. Is this possible?

I see that there is a popBackStack() function. However, I am a little confused on how this would work. Is it safe to use this function? Is there any possibility that an activity from a different application would be inserted after Bf on the backstack?

Also, is there any way to alter the savedInstanceState of the fragment on the backstack?

I just can't figure out how to do a robust test on the backstack using the emulator.

Answer 1

You can pop the fragment by name. While adding fragments to the back stack, just give them a name.

fragmentTransaction.addToBackStack("fragB"); fragmentTransaction.addToBackStack("fragC"); 

Then in Fragment_C, pop the back stack using the name ie.. fragB and include POP_BACK_STACK_INCLUSIVE

someButtonInC.setOnClickListener(new View.OnClickListener() {      @Override     public void onClick(View v) {          FragmentManager fm = getActivity()                 .getSupportFragmentManager();         fm.popBackStack ("fragB", FragmentManager.POP_BACK_STACK_INCLUSIVE);     } }); 

Answer 2

Three ways to pop Fragment off BackStack

Simply add any of these lines:

1)

getActivity().getSupportFragmentManager().popBackStack(); 

2)

getActivity().getSupportFragmentManager().popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE); 

3)

getActivity().getSupportFragmentManager().popBackStackImmediate(null, FragmentManager.POP_BACK_STACK_INCLUSIVE); 

They're all easy ways to pop fragment off Backstack