请求网络加载ListView Asynctack后台线程

MainActivity里的方法参数看一下代码：

import android.graphics.Bitmap;import android.os.AsyncTask;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.ListView;import android.widget.TextView;import com.google.gson.Gson;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {public String urlString="http://api.expoon.com/AppNews/getNewsList/type/1/p/1";    String urlBitmap="http://img.my.csdn.net/uploads/201407/26/1406383265_8550.jpg";    private ListView li;    private List<Javabing.DataBean> list;    private MybaseAdapter mb;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        li = (ListView) findViewById(R.id.li);        new Myasy().execute(urlString);        list = new ArrayList<Javabing.DataBean>();        Myasy my=new Myasy();        mb = new MybaseAdapter();        li.setAdapter(mb);        my.execute(urlString);    }    private class Myasy extends AsyncTask<String,Void,String>{        @Override        protected String doInBackground(String... strings) {            String str=strings[0];            String json = Netutil.getJson(str);            return json;        }        @Override        protected void onPostExecute(String s) {            super.onPostExecute(s);            Gson gson=new Gson();            Javabing ja = gson.fromJson(s, Javabing.class);            List<Javabing.DataBean> data = ja.getData();            list.addAll(data);            mb.notifyDataSetChanged();        }    }  class MybaseAdapter extends BaseAdapter{      @Override      public int getCount() {          return list.size();      }      @Override      public Object getItem(int i) {          return list.get(i);      }      @Override      public long getItemId(int i) {          return i;      }      @Override      public View getView(int i, View view, ViewGroup viewGroup) {          View vi = view.inflate(MainActivity.this, R.layout.two, null);          TextView te = vi.findViewById(R.id.te);          te.setText(list.get(i).getNews_summary());          ImageView im = vi.findViewById(R.id.im);           new MyAsynctask(im).execute(urlBitmap);          return vi;      }  }  private class MyAsynctask extends AsyncTask<String,Void,Bitmap>{      private ImageView im;      public MyAsynctask(ImageView im) {          this.im=im;      }      @Override      protected Bitmap doInBackground(String... strings) {          return  Netutil.getNetBitmap(strings[0]);      }      @Override      protected void onPostExecute(Bitmap bitmap) {          super.onPostExecute(bitmap);         im.setImageBitmap(bitmap);      }  }工具包Utils里的方法，如一下代码： 
public static String getJson(String urlString){    try {        URL url=new URL(urlString);        HttpURLConnection ur = (HttpURLConnection) url.openConnection();        int responseCode = ur.getResponseCode();         if (responseCode==200){             InputStream inpu = ur.getInputStream();             BufferedReader br=new BufferedReader(new InputStreamReader(inpu));             StringBuffer sb=new StringBuffer();             String line=null;             while ((line=br.readLine())!=null){                 sb.append(line);             }             return sb.toString();         }    } catch (MalformedURLException e) {        e.printStackTrace();    } catch (IOException e) {        e.printStackTrace();    }    return "";}public static Bitmap getNetBitmap(String urlString){    try {        URL url=new URL(urlString);        HttpURLConnection ur = (HttpURLConnection) url.openConnection();        int re = ur.getResponseCode();        if (re==200){            InputStream inputStream = ur.getInputStream();            Bitmap bitmap = BitmapFactory.decodeStream(inputStream);            return bitmap;        }    } catch (MalformedURLException e) {        e.printStackTrace();    } catch (IOException e) {        e.printStackTrace();    }    return null;}
然后自己在封装一个Javabing，用来解析Gson串,
中间适配器也需要XML文件，手动建造即可。