工厂模式加单例管理Fragment，同时解决fragment切换数据丢失问题

package com.itjfr.jfr.fragment;

import java.util.ArrayList;

import java.util.List;

import android.support.v4.app.Fragment;

import android.support.v4.app.FragmentManager;

/**

* 本工厂管理fragment保证所有的fragment为单例

*

* @author Nullifier

*

*/

public class FragmentFactory {

private static Fragment settingFragment;

private static HomeFragment homeFragment;

private static GuidanceFragment guidanceFragment;

private static MarketFragment marketFragment;

private static MeFragment meFragment;

private static PersonDetailFragment personDetailFragment;

private static ScoreFragment scoreFragment;

private static ImageFragment imageFragment;

//当前fragment缓存

private static Fragment cacheFragment;

public static Fragment getNowFragment() {

return cacheFragment;

}

/**

* 切换fragment工具方法 由于fragment经常切换如果使用replace方法则会造成fragment重新加载，所以只能hide/show

*

* @param target

* 目标切换的fragment

* @param resourceId

* 要替换的资源ID

* @param fagmentManager

* fragment管理者

*/

public static void switchPager(Fragment target, int resourceId,

FragmentManager fagmentManager) {

// 缓存cache第一次进来是空的要单独处理

if (cacheFragment == null) {

// 第一次进来要切换的fragment作为当前fragment加入到transaction中并显示

fagmentManager.beginTransaction().add(resourceId, target)

.show(target).commit();

// 将此fragment赋值给缓存fragment，停止代码执行

cacheFragment = target;

return;

}

// 如果目标fragment与当前fragment一样则直接返回不执行

if (cacheFragment == target) {

return;

}

// 如果目标frragment没有添加进来则添加进transaction中

if (!target.isAdded()) {

fagmentManager.beginTransaction().add(resourceId, target).commit();

}

// 隐藏当前的fragmeny显示目标的fragment

fagmentManager.beginTransaction().hide(cacheFragment).show(target)

.commit();

//将目标fragment复制给缓存标记

cacheFragment = target;

}

/**

* 获取fragment

*

* @param fragment类型

* FragmentType枚举

* @return fragment

*/

public static Fragment getFragment(FragmentType type) {

switch (type) {

case GUIDANCE:

if (guidanceFragment == null) {

guidanceFragment = new GuidanceFragment();

}

return guidanceFragment;

case HOME:

if (homeFragment == null) {

homeFragment = new HomeFragment();

}

return homeFragment;

case MARKET:

if (marketFragment == null) {

marketFragment = new MarketFragment();

}

return marketFragment;

case ME:

if (meFragment == null) {

meFragment = new MeFragment();

}

return meFragment;

case PERSONDETAIL:

if (personDetailFragment == null) {

personDetailFragment = new PersonDetailFragment();

}

return personDetailFragment;

case SCORE:

if (scoreFragment == null) {

scoreFragment = new ScoreFragment();

}

return scoreFragment;

case SETTING:

if (settingFragment == null) {

settingFragment = new SettingFragment();

}

return settingFragment;

case IMAGE:

if (imageFragment == null) {

imageFragment = new ImageFragment();

}

return imageFragment;

default:

break;

}

return null;

}

/**

* 通过网络地址集合获取fragment集合，集合不唯一

*

* @param type

* 类型 一般为IMAGE

* @param urlList

* 图片集合

* @return

*/

public static List<Fragment> getFragment(FragmentType type,

List<String> urlList) {

switch (type) {

case IMAGE:

ArrayList<Fragment> listFragment = new ArrayList<Fragment>();

if (urlList != null && urlList.size() > 0) {

for (int i = 0; i < urlList.size(); i++) {

listFragment.add(new ImageFragment().setIamgeUrl(urlList

.get(i)));

}

}

return listFragment;

default:

break;

}

return null;

}

/**

* 枚举

*

* @author Nullifier

*

*/

public static enum FragmentType {

/**

* 导航

*/

GUIDANCE,

/**

* 主页

*/

HOME,

/**

* 市场

*/

MARKET,

/**

* 我

*/

ME,

/**

* 个人详情

*/

PERSONDETAIL,

/**

* 积分

*/

SCORE,

/**

* 设置

*/

SETTING,

/**

* 图像

*/

IMAGE;

}

}