Fragment的初步用法

protected void replaceFragment(Fragment fragment , boolean init)
    {
        FragmentManager fragmentManager = this.getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        if(init)
        {
            fragmentTransaction.add(R.id.main_root, fragment);
        }
        else
        {
            fragmentTransaction.setCustomAnimations(R.anim.right_in    , R.anim.left_out , R.anim.left_in , R.anim.right_out);//添加切换进入和back键返回的动画
            fragmentTransaction.replace(R.id.main_root, fragment);//切换片段
            fragmentTransaction.addToBackStack(null);//并且加入stack中，以便返回
        }
        fragmentTransaction.commit();//提交
    }


private void addFragment()
    {
        FragmentManager fragmentManager = this.getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

        GalleryFlowFragment fragment = new GalleryFlowFragment();

        fragmentTransaction.add(R.id.main_root, fragment);//添加片段

        fragmentTransaction.commit();
    }


public void popFragment()
    {
        FragmentManager fragmentManager = getSupportFragmentManager();                
        fragmentManager.popBackStack();// 返回前一个片段
    }