Android通过XListView实现上拉加载下拉刷新功能

## 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;
  }