PullToRefreshListView上下拉刷新

原创于 2018-03-29 19:43:20 发布 · 145 阅读

CC 4.0 BY-SA版权

本文详细介绍了一个基于PullToRefresh的组件实现，包括如何在Android应用中集成该组件以实现下拉刷新和上拉加载更多功能。文中通过具体示例展示了如何设置PullToRefreshListView的模式、监听器，并实现网络数据请求及适配器更新。

首先添加依赖

compile 'com.github.userswlwork:pull-to-refresh:1.0.0'

public class Fragment01 extends Fragment {

    private PullToRefreshListView plv;
    private List<RequestData.NewslistBean> data = new ArrayList<>();
    private int pageType=10;
    private int pageIndex=1;
private String urlpath="http://api.tianapi.com/mobile/?key=71e58b5b2f930eaf1f937407acde08fe&num="+pageIndex;
    private MyAdapter adapter;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment01, container, false);
        plv = view.findViewById(R.id.plv);
        //初始化PullToRefreshListView
        initplv();
        requestNetData();



        return view;
    }

    private void requestNetData() {
        new MyTask().execute(urlpath);
    }

    private void initplv() {

        plv.setMode(PullToRefreshBase.Mode.BOTH);
        plv.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2<ListView>() {
            @Override
            public void onPullDownToRefresh(PullToRefreshBase<ListView> pullToRefreshBase) {
                pageIndex=10;
                pageType=1;
                urlpath="http://api.tianapi.com/mobile/?key=71e58b5b2f930eaf1f937407acde08fe&num="+pageIndex;
                requestNetData();
            }

            @Override
            public void onPullUpToRefresh(PullToRefreshBase<ListView> pullToRefreshBase) {
                pageIndex=pageIndex+10;
                pageType=2;
                urlpath="http://api.tianapi.com/mobile/?key=71e58b5b2f930eaf1f937407acde08fe&num="+pageIndex;
                requestNetData();
            }
        });

    }

    private String toJson(InputStream inputStream) {
        StringBuilder builder = new StringBuilder();
        String string;
        InputStreamReader in = new InputStreamReader(inputStream);
        BufferedReader reader = new BufferedReader(in);
        try {
            while ((string=reader.readLine())!=null){
                builder.append(string);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return builder.toString();
    }

    class MyTask extends AsyncTask<String,Void,String> {

        @Override
        protected String doInBackground(String... strings) {
            String str="";
            try {
                URL url = new URL(strings[0]);
                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                urlConnection.setRequestMethod("GET");
                urlConnection.setConnectTimeout(5000);
                urlConnection.setReadTimeout(5000);
                int responseCode = urlConnection.getResponseCode();
                if (responseCode==200){
                    InputStream inputStream = urlConnection.getInputStream();
                    str=toJson(inputStream);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return str;
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);

            Gson gson = new Gson();
            RequestData requestData = gson.fromJson(s, RequestData.class);
            List<RequestData.NewslistBean> newslist = requestData.getNewslist();
            if (pageType==1){
                data.clear();
            }
            data.addAll(newslist);
            setlvadapter();
            //关闭头尾布局
            plv.onRefreshComplete();

        }
    }


    private void setlvadapter() {
        if (adapter ==null){
            adapter = new MyAdapter(data,getActivity());
            plv.setAdapter(adapter);
        }else{
            adapter.notifyDataSetChanged();
        }

    }

}