fragment卡片选择（RadioGroup + fragment）

 public void setTabSelection(int index) {
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        hideFragments(transaction);
        Fragment frament = null;
        switch (index) {
            case 0:
                if (fragment1 == null) {
                    // 如果MessageFragment为空，则创建一个并添加到界面上
//                    firstPageFragment = new FirstPageFragment(menu1);
                    fragment1 = HomeFragment.newInstance();
                    transaction.add(R.id.container, fragment1);
                } else {
                    // 如果MessageFragment不为空，则直接将它显示出来
                    transaction.show(fragment1);
                }
                break;
            case 1:
                if (fragment2 == null) {
                    // 如果MessageFragment为空，则创建一个并添加到界面上
                    fragment2 = SceneFragment.newInstance();
                    transaction.add(R.id.container, fragment2);
                } else {
                    // 如果MessageFragment不为空，则直接将它显示出来
                    transaction.show(fragment2);
                }
                break;
            case 2:
                if (fragment3 == null) {
                    // 如果MessageFragment为空，则创建一个并添加到界面上
                    fragment3 = MineFragment.newInstance();
                    transaction.add(R.id.container, fragment3);
                } else {
                    // 如果MessageFragment不为空，则直接将它显示出来
                    transaction.show(fragment3);
                }

                break;
        }
        transaction.commit();
    }


    private void hideFragments(FragmentTransaction transaction) {
        if (fragment1 != null) {
            transaction.hide(fragment1);
        }
        if (fragment2 != null) {
            transaction.hide(fragment2);
        }

        if (fragment3 != null) {
            transaction.hide(fragment3);
        }
    }