Android获取流量信息

Note:纯属自己工作总结,好久没些博客了, 对自己这些年的工作做个记录 .

public class TrafficInfoActivity extends Activity {
//展示数据列表
private ListView lv;
//获取到所有具有Intenet权限的应用的流量信息
private TrafficInfoProvider provider;
//ProgressBar和TextView（正在加载...）的父控件，用于控制其显示
private LinearLayout ll_loading;
//封装单个具有Intenet权限的应用的流量信息
private List<TrafficInfo>  trafficInfos;
//处理子线程发送过来的消息，更新UI
private Handler handler = new Handler(){
public void handleMessage(android.os.Message msg) {
ll_loading.setVisibility(View.INVISIBLE);
lv.setAdapter(new TrafficAdapter());
};
};
@Override
protected void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.traffic_info);
super.onCreate(savedInstanceState);
lv = (ListView) findViewById(R.id.lv_traffic_manager);
provider = new TrafficInfoProvider(this);
ll_loading = (LinearLayout) findViewById(R.id.ll_loading);
ll_loading.setVisibility(View.VISIBLE);
//获取到具有Internet权限的应用所产生的流量
new Thread(){
public void run() {
trafficInfos = provider.getTrafficInfos();
//想主线程中发送一个空消息，用于通知主线程更新数据
handler.sendEmptyMessage(0);
};
}.start();
}
//数据适配器
private class TrafficAdapter extends BaseAdapter{


public int getCount() {
return trafficInfos.size();
}


public Object getItem(int position) {
return trafficInfos.get(position);
}


public long getItemId(int position) {
return position;
}
//ListView中显示多少个Item，该方法就被调用多少次
public View getView(int position, View convertView, ViewGroup parent) {
View view;
ViewHolder holder = new ViewHolder();
TrafficInfo info = trafficInfos.get(position);
//复用缓存的View
if(convertView==null){
view = View.inflate(getApplicationContext(), R.layout.traffic_item, null);
holder.iv_icon = (ImageView) view.findViewById(R.id.iv_traffic_icon);
holder.tv_name = (TextView) view.findViewById(R.id.tv_traffic_name);
holder.tv_rx = (TextView) view.findViewById(R.id.tv_traffic_rx);
holder.tv_tx = (TextView) view.findViewById(R.id.tv_traffic_tx);
holder.tv_total = (TextView) view.findViewById(R.id.tv_traffic_total);
view.setTag(holder);
}else{
view = convertView;
holder = (ViewHolder) view.getTag();
}
holder.iv_icon.setImageDrawable(info.getIcon());
holder.tv_name.setText(info.getAppname());
//下载所产生的流量
long rx = info.getRx();
//上传所产生的流量
long tx = info.getTx();
//增强程序的健壮性。因为在模拟器上运行时返回值为-1.
if(rx<0){
rx = 0;
}
if(tx<0){
tx = 0;
}
holder.tv_rx.setText(Formatter.formatFileSize(getApplicationContext(), rx));
holder.tv_tx.setText(Formatter.formatFileSize(getApplicationContext(), tx));
//总流量
long total = rx + tx;
//通过Formatter将long类型的数据转换为MB或这KB，当数字较小时，自动采用KB
holder.tv_total.setText(Formatter.formatFileSize(getApplicationContext(), total));
return view;
}
}
//通过static的修饰，保证了栈内存中存在唯一一份字节码且被共用
static class ViewHolder{
ImageView iv_icon;
TextView tv_name;
TextView tv_tx;
TextView tv_rx;
TextView tv_total;
}
}