ViewPager+Fragment+GridView方案notifyDataSetChanged()无法刷新数据问题

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采用ViewPager+Fragment+GridView方案实现类似qq的多屏滑动的效果，但是在运行问题中发现了第三屏的GridView修改数据是无法刷新，采用notifyDataSetChanged()也无法刷新，在网上找了很多例子多是讲到在FragmentPagerAdapter中除清缓存，经过验证只做这步是不行的，无奈之下只能从Fragment生命周期入手。结合网上的例子给出了解决方案：

首先是MyFragmentPagerAdapter.java

import android.support.v4.app.Fragment;import android.support.v4.app.FragmentManager;import android.support.v4.app.FragmentPagerAdapter;import android.support.v4.app.FragmentTransaction;/** *  * @author Tom.Cai * */public class MyFragmentPagerAdapter extends FragmentPagerAdapter {    private ArrayList<Fragment> fragments;    private FragmentManager fm;        public MyFragmentPagerAdapter(FragmentManager fm) {    super(fm);    }    public MyFragmentPagerAdapter(FragmentManager fm, ArrayList<Fragment> fragments) {        super(fm);        this.fm = fm;        this.fragments = fragments;    }    @Override    public int getCount() {        return fragments.size();    }    @Override    public Fragment getItem(int arg0) {        return fragments.get(arg0);    }    @Override    public int getItemPosition(Object object) {        return POSITION_NONE;    }        public void setFragmentsList(ArrayList<Fragment> fragmentsList) {    if(this.fragments != null){    FragmentTransaction ft = fm.beginTransaction();    for(Fragment f:fragmentsList){    ft.remove(f);    }    ft.commit();    ft= null;    this.fragments = fragmentsList;    notifyDataSetChanged();    }}}

然后是the GridView inside of Fragment

/** * @Function: 第三个屏幕 * @Date: 2013-12-11 * @Time: 下午3:45:32 * @author Tom.Cai */public class ThreeFragment extends Fragment {private GridView gridview;private ArrayList<HashMap<String, Object>> listImageItem;private SimpleAdapter simpleAdapter;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {  View view = inflater.inflate(R.layout.threefragment, container, false);  InitView(view);  InitListener();  return view;}private void InitView(View view) {gridview = (GridView) view.findViewById(R.id.gridview);}private void InitListener() {gridview.setOnItemClickListener(new MyItemClickListener());gridview.setOnItemLongClickListener(new MyItemLongClickListener());}@Overridepublic void onStart() {// 生成动态数组，并且转入数据 #在onStart()方法中加载数据，就在Fragment中可以动态刷新数据#listImageItem = new ArrayList<HashMap<String, Object>>();for (int i = 0; i < 9; i++) {HashMap<String, Object> map = new HashMap<String, Object>();  map.put("ItemImage", R.drawable.user);// 添加图像资源的IDmap.put("ItemText", i+"");// 按序号做ItemTextlistImageItem.add(map);}}simpleAdapter = new SimpleAdapter(getActivity().getApplicationContext(), listImageItem,R.layout.contact_list_item_gridview, new String[] {"ItemImage", "ItemText" }, new int[] { R.id.displayImg,R.id.displayName });//添加图片绑定simpleAdapter.setViewBinder(new ViewBinder() {public boolean setViewValue(View view, Object data,String textRepresentation) {if (view instanceof ImageView && data instanceof Drawable) {ImageView iv = (ImageView) view;iv.setImageDrawable((Drawable) data);return true;} elsereturn false;}});gridview.setAdapter(simpleAdapter);super.onStart();}}

除了在MyFragentPagerAdapter中清除缓存外，另外重要的是在onStart()方法中加载数据，就在Fragment中可以动态刷新数据，本例中就是生产动态数组和setAdapt();

更多文章请查看我的博客：http://blog.csdn.net/caicongyang

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