Android_检测当前网速

思路步骤：
1、Android提供有获取当前总流量的方法
2、上一秒 减去 下一面的流量差便是网速
3、注意计算

1>计算网速的工具类：

package imcs.cb.com.viewapplication.utils;

import android.content.Context;
import android.net.TrafficStats;
import android.os.Handler;
import android.os.Message;

import java.util.Timer;
import java.util.TimerTask;

/**
 * Created by Ricky on 2016/10/13.
 */
public class NetWorkSpeedUtils {
    private Context context;
    private Handler mHandler;

    private long lastTotalRxBytes = 0;
    private long lastTimeStamp = 0;

    public NetWorkSpeedUtils(Context context, Handler mHandler){
        this.context = context;
        this.mHandler = mHandler;
    }

    TimerTask task = new TimerTask() {
        @Override
        public void run() {
            showNetSpeed();
        }
    };

    public void startShowNetSpeed(){
        lastTotalRxBytes = getTotalRxBytes();
        lastTimeStamp = System.currentTimeMillis();
        new Timer().schedule(task, 1000, 1000); // 1s后启动任务，每2s执行一次

    }

    private long getTotalRxBytes() {
        return TrafficStats.getUidRxBytes(context.getApplicationInfo().uid) == TrafficStats.UNSUPPORTED ? 0 :(TrafficStats.getTotalRxBytes()/1024);//转为KB
    }

    private void showNetSpeed() {
        long nowTotalRxBytes = getTotalRxBytes();
        long nowTimeStamp = System.currentTimeMillis();
        long speed = ((nowTotalRxBytes - lastTotalRxBytes) * 1000 / (nowTimeStamp - lastTimeStamp));//毫秒转换
        long speed2 = ((nowTotalRxBytes - lastTotalRxBytes) * 1000 % (nowTimeStamp - lastTimeStamp));//毫秒转换

        lastTimeStamp = nowTimeStamp;
        lastTotalRxBytes = nowTotalRxBytes;

        Message msg = mHandler.obtainMessage();
        msg.what = 100;
        msg.obj = String.valueOf(speed) + "." + String.valueOf(speed2) + " kb/s";
        mHandler.sendMessage(msg);//更新界面
    }
}

2>使用：

   private Handler mHnadler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case 100:
                    tv_speed.setText("当前网速： " + msg.obj.toString());
                    break;
            }
            super.handleMessage(msg);
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tv_speed = (TextView) findViewById(R.id.tv_speed);

        new NetWorkSpeedUtils(this,mHnadler).startShowNetSpeed();
    }