切换

package com.bawei.zhaoqian20170724;
/**
 * 作者: 赵虔
 * 时间: 2017/7/24
 * 类作用:用于网络请求数据,把请求到的数据解析出来,最后适配给XListView
 */

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;

import com.bawei.zhaoqian20170724.Bean.MenuInfo;
import com.bawei.zhaoqian20170724.Utils.StringTools;
import com.google.gson.Gson;
import com.limxing.xlistview.view.XListView;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;

public class MainActivity extends AppCompatActivity implements XListView.IXListViewListener {

    private XListView xlistview;
    private int index = 1;
    private MyBaseAdapter adapter;
    private boolean boo;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //寻找控件
        xlistview = (XListView) findViewById(R.id.xlistview);
        xlistview.setPullLoadEnable(true);
        xlistview.setXListViewListener(this);
        //通过指定接口请求数据
        getData("http://qhb.2dyt.com/Bwei/news?type=" + index + "&postkey=ad1AK");
    }

    //    通过指定接口请求数据
    private void getData(String path) {
        new AsyncTask<String, Void, String>() {
            @Override
            protected void onPostExecute(String s) {
                super.onPostExecute(s);
                if (s != null) {
//                    使用Gson解析请求到的数据
                    Gson gson = new Gson();
                    MenuInfo info = gson.fromJson(s, MenuInfo.class);
                    List<MenuInfo.ListBean> list = info.getList();
//                    把数据回调给Xlistview的适配器加载数据
                    if (adapter == null) {
                        adapter = new MyBaseAdapter(list);
                        xlistview.setAdapter(adapter);
                    } else {
                        adapter.addData(list, boo);
                        adapter.notifyDataSetChanged();
                    }
                }
            }

            @Override
            protected String doInBackground(String... params) {
                try {
//                    得到路径,实例化HttpURLConnection对象
                    URL url = new URL(params[0]);
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//                    设置请求方式
                    connection.setRequestMethod("GET");
//                    设置请求数据的时间
                    connection.setConnectTimeout(5000);
//                    设置读取数据的时间
                    connection.setReadTimeout(5000);
//                    判断响应,如果==200说明请求成功
                    if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
//                        得到请求的数据流
                        InputStream is = connection.getInputStream();
//                        把请求到的数据流转换成String类型返回
                        return StringTools.getJson(is);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;
            }
        }.execute(path);
    }

    //下拉刷新
    @Override
    public void onRefresh() {
        ++index;
        getData("http://qhb.2dyt.com/Bwei/news?type=" + index + "&postkey=ad1AK");
        boo = true;
        xlistview.stopRefresh(true);
    }

    //上啦加载
    @Override
    public void onLoadMore() {
        ++index;
        getData("http://qhb.2dyt.com/Bwei/news?type=" + index + "&postkey=ad1AK");
        boo = false;
        xlistview.stopLoadMore();
    }

    //    Xlistview 自定义适配器
    class MyBaseAdapter extends BaseAdapter {
        private List<MenuInfo.ListBean> list;

        public MyBaseAdapter(List<MenuInfo.ListBean> list) {
            this.list = list;
        }

        /**
         * 判断,如果是true就是在下拉刷新,数据从0下标开始添加显示在最前面
         * 如果是false就是在上啦加载,数据从默认从最后面加载
         *
         * @param data 新请求到的数据
         * @param b    用于判断是在下拉刷新还是上啦加载
         */

        private void addData(List<MenuInfo.ListBean> data, boolean b) {
            for (MenuInfo.ListBean bean : data) {
                if (b)
                    list.add(0, bean);
                else
                    list.add(bean);
            }
        }

        @Override
        public int getCount() {
            return list != null ? list.size() : 0;
        }

        @Override
        public Object getItem(int position) {
            return list.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder0 holder0 = null;
            ViewHolder1 holder1 = null;
            int type = getItemViewType(position);
//            根据item 的type来添加数据
            switch (type) {
                case 0:
                    if (convertView == null) {
                        convertView = View.inflate(MainActivity.this, R.layout.item0, null);
                        holder0 = new ViewHolder0();
                        holder0.left = (ImageView) convertView.findViewById(R.id.imgleft);
                        holder0.right = (ImageView) convertView.findViewById(R.id.imgright);
                        convertView.setTag(holder0);
                    } else {
                        holder0 = (ViewHolder0) convertView.getTag();
                    }
                    //从请求到的数据中得到pic的图片路劲,把路劲通过"|"分割
                    String[] split = list.get(position).getPic().split("\\|");
//                    使用ImageLoader加载图片
                    setImage(split[0 < (split.length - 1) ? 0 : 0], holder0.left);
                    setImage(split[1 < (split.length - 1) ? 1 : 0], holder0.right);
                    break;

                case 1:
                    if (convertView == null) {
                        convertView = View.inflate(MainActivity.this, R.layout.item1, null);
                        holder1 = new ViewHolder1();
                        holder1.topleft = (ImageView) convertView.findViewById(R.id.imgTopleft);
                        holder1.topright = (ImageView) convertView.findViewById(R.id.imgTopright);
                        holder1.bottomleft = (ImageView) convertView.findViewById(R.id.imgBottomleft);
                        holder1.bottomright = (ImageView) convertView.findViewById(R.id.imgBottomright);
                        convertView.setTag(holder1);
                    } else {
                        holder1 = (ViewHolder1) convertView.getTag();
                    }
                    //从请求到的数据中得到pic的图片路劲,把路劲通过"|"分割
                    String[] split1 = list.get(position).getPic().split("\\|");
//                    使用ImageLoader加载图片
                    setImage(split1[0 < (split1.length - 1) ? 0 : 0], holder1.topleft);
                    setImage(split1[1 < (split1.length - 1) ? 1 : 0], holder1.topright);
                    setImage(split1[2 < (split1.length - 1) ? 2 : 0], holder1.bottomleft);
                    setImage(split1[3 < (split1.length - 1) ? 3 : 0], holder1.bottomright);
                    break;
            }

            return convertView;
        }

        //        得到type的总数
        @Override
        public int getViewTypeCount() {
            return 2;
        }

        //        得到每一个item的type
        @Override
        public int getItemViewType(int position) {
            if (position % 2 == 0)
                return 0;
            else
                return 1;
        }
    }

    class ViewHolder0 {
        ImageView left;
        ImageView right;
    }

    class ViewHolder1 {
        ImageView topleft;
        ImageView topright;
        ImageView bottomleft;
        ImageView bottomright;
    }

    //    自定义方法使用ImageLoader加载图片
    private void setImage(String path, ImageView img) {
//        自定加载图片
        DisplayImageOptions build = new DisplayImageOptions.Builder()
                .cacheInMemory(true)
                .cacheOnDisk(true)
                .showImageForEmptyUri(R.mipmap.ic_empty)
                .showImageOnLoading(R.mipmap.loading)
                .showImageOnFail(R.mipmap.ic_error)
                .build();
//        把图片按照自定义方式加载
        ImageLoader.getInstance().displayImage(path, img, build);
    }
}