生产Fragment的工厂类

    package com.itheima.googleplay74.ui.fragment;

    import java.util.HashMap;

    /**
     * 生产fragment工厂
    * 
    * @author Kevin
    * @date 2015-10-27
    */
    public class FragmentFactory {

    private static HashMap<Integer, BaseFragment> mFragmentMap = new HashMap<Integer, BaseFragment>();

    public static BaseFragment createFragment(int pos) {
        // 先从集合中取, 如果没有,才创建对象, 提高性能
        BaseFragment fragment = mFragmentMap.get(pos);

        if (fragment == null) {
            switch (pos) {
            case 0:
                fragment = new HomeFragment();
                break;
            case 1:
                fragment = new AppFragment();
                break;
            case 2:
                fragment = new GameFragment();
                break;
            case 3:
                fragment = new SubjectFragment();
                break;
            case 4:
                fragment = new RecommendFragment();
                break;
            case 5:
                fragment = new CategoryFragment();
                break;
            case 6:
                fragment = new HotFragment();
                break;

            default:
                break;
            }

            mFragmentMap.put(pos, fragment);// 将fragment保存在集合中
        }

        return fragment;
        }
    }