点击切换Fragment

ArrayList<Fragment> list = new ArrayList<>();
        Frag1Fragment frag1 = new Frag1Fragment();
        Frag2Fragment frag2 = new Frag2Fragment();
        list.add(frag1);
        list.add(frag2);
        manager = getSupportFragmentManager();
        manager.beginTransaction().replace(R.id.frag_ment,frag1).commit();
        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                FragmentTransaction transaction = manager.beginTransaction();
                switch (checkedId){
                    case R.id.btn_1:
                        transaction.replace(R.id.frag_ment,frag1);
                    break;
                    case R.id.btn_2:
                        transaction.replace(R.id.frag_ment,frag2);
                    break;

                }
                transaction.commit();
            }
        });