Android访问网络：服务端返回XML或JSON格式数据，Android 进行解析并使用ListView显示

刚刚入门学习了Android的ListView，也是看了传智播客黎活明老师的视频学习了，但是一直运行不了，还报错了。报的错误是：at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1......省略后面的了。。。。。后面上网查找了一下资料，原因是Android4.0以后访问网络要在子线程里执行；不能在主程序里执行。查找了一下资料对这个例子进行了改进，下面链接的例子代码就是视频里面的差不多的代码：http://blog.csdn.net/lynxzong/article/details/12435451

下面的是我在这个例子上改过的代码，只是改动了MainActivity而已，其他的跟上面链接的代码一样的。希望各位多多指导；有写错或者写不好的地方求改正。。。

package com.example.videonews;

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

import com.example.domain.News;
import com.example.service.VideoNewsService;

import android.support.v7.app.ActionBarActivity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity {

private Context context;
private ListView listview;
private ProgressDialog dialog;
private SimpleAdapter adapter;
private VideoNewsService videoNewsService;
private List<News> videosList = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

context = MainActivity.this;

/**初始化界面**/
initView();

/**加载基本的控件，并设置加载时候的滚动条**/
dialog = new ProgressDialog(context);
dialog.setMessage("正在加载数据...");
dialog.setCancelable(false);
dialog.show();
Thread thread=new Thread(new loadListRunnable());
thread.start();

}



/**
 * *初始化界面
 */
private void initView() {
listview=(ListView) findViewById(R.id.listview);
}

public class loadListRunnable implements Runnable {

@Override
public void run() {

try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}

videoNewsService=new VideoNewsService();
try {

//videosList=videoNewsService.getLastNews();//读取xml文件
videosList=videoNewsService.getJSONLastNews(); //读取json
Bundle bundle=new Bundle();
if(null!=videosList && videosList.size()>0)
{
bundle.putString("result", "success");
Message message=new Message();
message.setData(bundle);
handler.sendMessage(message);
}
else
{
bundle.putString("result", "fail");
}

} catch (Exception e) {
e.printStackTrace();
}

}

}

/**
 * 对返回的数据进行处理
 */
private Handler handler=new Handler(){

public void handleMessage(Message msg)
{
String msStr=msg.getData().getString("result");
if("success".equals(msStr))
{
//加载数据赋值
initListView();
//数据加载完成后结束进度条
dialog.dismiss();
}
else{
Toast.makeText(getApplicationContext(), "获取数据失败", 0).show();
}
}
};

protected void initListView() {

List<HashMap<String, Object>> data=new ArrayList<HashMap<String,Object>>();
    for(News news:videosList)
    {
    HashMap<String, Object> item=new HashMap<String, Object>();
    item.put("id", news.getId());
    item.put("title", news.getTitle());
    item.put("timelength", getResources().getString(R.string.timelength)+
    news.getTimelength()+getResources().getString(R.string.fenzhong));
    data.add(item);
    }
SimpleAdapter adapter=new SimpleAdapter(this, data, R.layout.items, 
new String[]{"title","timelength"}, new int[]{R.id.title,R.id.timelength});

listview.setAdapter(adapter);
}

}