通过XListView实现上拉加载下拉刷新

## 导入XListVIew第三方库文件。通过LinkedList将刷新数据插入到集合头部，将加载的数据放入集合尾部 ##
    private Context context;
    private View view;
    private String path;
    private XListView xlv;
    private LinkedList<Data> listData;

    private Handler handler = new Handler() {

        @SuppressWarnings("unchecked")
        public void handleMessage(android.os.Message msg) {

            int code = msg.arg1;
            if(msg.arg1==400){
                Toast.makeText(context, "数据格式解析不正确", 0).show();
            }
            else{
                NewsFragmentAdapter myAdapter = null;
                switch (code) {
                case 0:
                    // 默认
                    listData = (LinkedList<Data>) msg.obj;
                    myAdapter = new NewsFragmentAdapter(context, listData);
                    xlv.setAdapter(myAdapter);
                    break;
                case 1:
                    LinkedList<Data> shualist = (LinkedList<Data>) msg.obj;
                    myAdapter = new NewsFragmentAdapter(context, shualist);
                    for (int i = 0; i < shualist.size(); i++) {
                        listData.addFirst(shualist.get(i));
                    }
                    myAdapter.notifyDataSetChanged();
                    stopLoadOrRefresh();
                    break;
                case 2:
                    LinkedList<Data> loadlist = (LinkedList<Data>) msg.obj;
                    myAdapter = new NewsFragmentAdapter(context, loadlist);
                    for (int i = 0; i < loadlist.size(); i++) {
                        listData.addLast(loadlist.get(i));
                    }
                    myAdapter.notifyDataSetChanged();
                    stopLoadOrRefresh();
                    break;
                default:
                    break;
                }
            }
        };
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        context=getActivity();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment, container, false);

        path = getArguments().getString("path");

        // 配置Xlist
        xlv = (XListView) view.findViewById(R.id.xlv);  // 获得控件
        xlv.setPullRefreshEnable(true);                 // 设置可以下拉刷新
        xlv.setPullLoadEnable(true);                    // 设置可以上拉加载
        xListViewListener();                            // 调用XListView的监听方法

        if(path != null){
            getMessage(path, 0);                        // 调用方法请求数据
        }

        itemClickListner();                             // 调用XListView条目点击监听方法
        return view;
    }

    private void itemClickListner() {

        xlv.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
                Intent intent=new Intent(context, WebViewActivity.class);
                intent.putExtra("path", listData.get(arg2-1).article_url);
                startActivity(intent);
            }
        });
    }

    public void xListViewListener() {
        xlv.setXListViewListener(new IXListViewListener() {

            // 当下拉刷新时实现的操作
            @Override
            public void onRefresh() {
                getMessage(path, 1);    // 请求网络，将新请求的内容加载到集合前端
            }

            // 当上拉加载时实现的操作内容
            @Override
            public void onLoadMore() {  // 请求网络，将请求的新内容加载到集合后端
                getMessage(path, 2);
            }
        });

    }

    public void getMessage(String path, final int code) {

        HttpUtils utils = new HttpUtils();

        // 设置刷新间隔时间，如果不设置默认一分钟后才能刷新出新内容
        utils.configCurrentHttpCacheExpiry(0);

        utils.send(HttpMethod.GET, path, new RequestCallBack<String>() {

            // 请求网络失败回调的方法
            @Override
            public void onFailure(HttpException arg0, String arg1) {
            }

            // 请求网络成功回调的方法
            @Override
            public void onSuccess(ResponseInfo<String> arg0) {
                String info = arg0.result;

                Gson gson = new Gson();
                LinkedList<Data> list = gson.fromJson(info, ModelBean.class).data;
                Message message = new Message();
                if(list != null){
                    message.arg1 = code;
                    message.obj = list;
                }else{
                    message.arg1=400;
                }
                handler.sendMessage(message);
            }
        });
    }

    private void stopLoadOrRefresh() {
        // 停止加载
        xlv.stopLoadMore();
        // 停止刷新
        xlv.stopRefresh();
        // 最近一次刷新时间
        xlv.setRefreshTime(getTime());
    }

    public String getTime() {
        // 格式化时间
        SimpleDateFormat format = new SimpleDateFormat("hh:mm:ss");
        Date date = new Date();
        String time = format.format(date);
        return time;
    }