android实现tab个数少且固定，fragment不同时切换

private QuotesChildCollectFragment f2;
private QuotesChildCollectFragment f1;
private void setTabSelection(int index) {
//getSupportFragmentManager()  ，getParentFragmentManager()
        FragmentTransaction ft = getChildFragmentManager().beginTransaction();
        hideFragment(ft);
        switch (index) {
            case IConstants.COLLECT_CONTRACT:
                if (f1== null) {
                    f1 = QuotesChildCollectFragment.newInstance(index);
                    ft.add(R.id.fl_container, f1);
                } else {
                    ft.show(f1);
                }
                break;
            case IConstants.COLLECT_BIBI:
                if (f2 == null) {
                    f2 = QuotesChildCollectFragment.newInstance(index);
                    ft.add(R.id.fl_container, f2);
                }
                ft.show(f2);
                break;
        }
        ft.commit();
    }
    //隐藏所有的fragment
    private void hideFragment(FragmentTransaction transaction){
        if(f1 != null){
            transaction.hide(f1);
        }
        if(f2 != null){
            transaction.hide(f2);
        }
    }

调用时默认选择一个

setTabSelection(IConstants.COLLECT_CONTRACT);

切换时：

mRadioGroup.setOnCheckedChangeListener((group, checkedId) -> {
            if (checkedId == R.id.rb_default_data_contract) {
                setTabSelection(IConstants.COLLECT_CONTRACT);
            }else if(checkedId == R.id.rb_default_data_bibi) {
                setTabSelection(IConstants.COLLECT_BIBI);
            }
        });

布局要求:用FrameLayout装载fragment

<FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/fl_container"/>

当fragment个数不固定或者需要从网络请求中获取fragment个数时（一般fragment内容一样），可以使用TabLayout或者第三方的库MagicIndicator（https://github.com/hackware1993/MagicIndicator）