Handler请求数据+PullToRefreshListView

最新推荐文章于 2019-01-17 15:59:55 发布

原创最新推荐文章于 2019-01-17 15:59:55 发布 · 133 阅读

0 ·

CC 4.0 BY-SA版权

本文介绍了一个使用Fragment加载网络图片并实现下拉刷新和上拉加载更多功能的安卓应用示例。通过PullToRefreshListView组件和Universal Image Loader库，实现了高效的数据加载和图片显示。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

package com.example.kanghuwei20181215.fragment;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;

import com.example.kanghuwei20181215.NetUtils;
import com.example.kanghuwei20181215.R;
import com.example.kanghuwei20181215.adapter.MyPullToRefresh;
import com.example.kanghuwei20181215.bean.ListBean;
import com.google.gson.Gson;
import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshListView;
import com.nostra13.universalimageloader.core.ImageLoader;

import java.util.ArrayList;
import java.util.List;

public class Frag_01 extends Fragment {
    private String url = "http://api.tianapi.com/meinv/?key=3304a8bc9414f97e30928b80163cf098&num=10";
    private PullToRefreshListView plv;
    private ArrayList<ListBean.NewslistBean>list = new ArrayList<>();
    private ImageLoader imageLoaderstance;
    private MyPullToRefresh ptrfadapter;
    private int page;
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            if (msg.what == 1){
                String json =(String) msg.obj;
                Gson gson = new Gson();
                ListBean listBean = gson.fromJson(json, ListBean.class);
                List<ListBean.NewslistBean> newslist = listBean.getNewslist();
                list.addAll(newslist);
                ptrfadapter.notifyDataSetChanged();
                plv.onRefreshComplete();
            }
        }
    };
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.frag_01,container,false);
        plv = view.findViewById(R.id.plv);
        imageLoaderstance = ImageLoader.getInstance();
        ininData(page);
        ptrfadapter = new MyPullToRefresh(list,getActivity(),imageLoaderstance);
        plv.setAdapter(ptrfadapter);
        plv.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2<ListView>() {
            @Override
            public void onPullDownToRefresh(PullToRefreshBase<ListView> pullToRefreshBase) {
                page = 0;
                list.clear();
                ininData(page);
            }

            @Override
            public void onPullUpToRefresh(PullToRefreshBase<ListView> pullToRefreshBase) {
                page++;
                ininData(page);
            }
        });
        plv.setMode(PullToRefreshBase.Mode.BOTH);
        return view;
    }
    private void ininData(final int page){
        new Thread(){
            @Override
            public void run() {
                super.run();
                String json = NetUtils.getJson(url+page);
                Message message = handler.obtainMessage();
                message.what = 1;
                message.obj = json;
                handler.sendMessage(message);
            }
        }.start();
    }

}