Pass data back to previous fragment using Android Navigation

问题

I've started using Android Architecture Components (Navigation and Safe Args, View Models) along with Koin library.

Currently, I've got a problem with passing arguments between two fragments - I need to pass a string value from fragment A to fragment B, modify this value in fragment B and pass it back to fragment A.

I've found one possible solution to my problem - shared view models. Unfortunately, this approach has one problem because I can pass and modify values between screens, but when the fragment A navigate to another destination the value in the shared view model is still stored and not cleared.

Is there any different solution of passing and modifying data between fragments in Android Navigation? I want to avoid clearing this one value by hand (when the fragment A is destroyed).

回答1:

1) Pass string from Fragment A to Fragment B with action_A_to_B and SafeArgs.

2) popBackStack to remove Fragment B.

navController.popBackStack(R.id.AFragment, false);

or

navController.popBackStack();

3) Then pass modified data from B to A with action_B_to_A.

EDIT.

Here you have some another solution

来源：https://stackoverflow.com/questions/56243119/pass-data-back-to-previous-fragment-using-android-navigation