网络状态监控

实时获取网络的上下行数据状态：

    long uidRxBytes;
    long uidRxPackets;
    long uidTxBytes;
    long uidTxPackets;

    public void getInfo() {
        int uid = getApplicationInfo().uid;
        uidRxBytes = TrafficStats.getUidRxBytes(uid) - uidRxBytes;
        uidRxPackets = TrafficStats.getUidRxPackets(uid) - uidRxPackets;
        uidTxBytes = TrafficStats.getUidTxBytes(uid) - uidTxBytes;
        uidTxPackets = TrafficStats.getUidTxPackets(uid) - uidTxPackets;
        String info = String.format("uidRxBytes=%d,uidRxPackets=%d,uidTxBytes=%d,uidTxPackets=%d",
                uidRxBytes, uidRxPackets, uidTxBytes, uidTxPackets
        );
        System.out.println("info=" + info);
    }