从活动Android调用片段方法

Question

I know this issue was discussed many times, but no solution works for me. I have an activity with fragment attached and using interface I'm calling a method from my activity that is replacing this fragment with another one. I want this method also to call a method from my new 'fragment', but however I implement that the application crashes when reaching this point. Does somebody know a solution for that? I'm new to Android development.

public void replacingMethod(String text){

    NewFragment newFragment = new NewFragment();
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.fragment_container, newFragment).addToBackStack(null).commit();

    NewFragment f = (NewFragment) getSupportFragmentManager().findFragmentById(R.id.new_fragment);
    f.displayText(text);
}

I've tried to call displayText() from newFragment before and after replacement but it didn't work.

Answer 1

尝试使用R.id.fragment_container而不是R.id.new_fragment获取片段。

Answer 2

Your fragment should be attached to the activity to display text. The right way is to pass the text you want to show to the fragment using it's arguments with Fragment#setArguments(Bundle) and then get it inside fragment using Fragment#getArguments() .