public class NetWorkStateReceiver extends BroadcastReceiver {    @Override    public void onReceive(Context context, Intent intent) {        System.out.println("网络状态发生变化");        //检测API是不是小于23，因为到了API23之后getNetworkInfo(int networkType)方法被弃用        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP) {            //获得ConnectivityManager对象            ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);            //获取ConnectivityManager对象对应的NetworkInfo对象            //获取WIFI连接的信息            NetworkInfo wifiNetworkInfo = connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);            //获取移动数据连接的信息            NetworkInfo dataNetworkInfo = connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);            if (wifiNetworkInfo.isConnected() && dataNetworkInfo.isConnected()) {                Toast.makeText(context, "WIFI已连接,移动数据已连接", Toast.LENGTH_SHORT).show();            } else if (wifiNetworkInfo.isConnected() && !dataNetworkInfo.isConnected()) {                Toast.makeText(context, "WIFI已连接,移动数据已断开", Toast.LENGTH_SHORT).show();            } else if (!wifiNetworkInfo.isConnected() && dataNetworkInfo.isConnected()) {                Toast.makeText(context, "WIFI已断开,移动数据已连接", Toast.LENGTH_SHORT).show();            } else {                Toast.makeText(context, "WIFI已断开,移动数据已断开", Toast.LENGTH_SHORT).show();            }//API大于23时使用下面的方式进行网络监听        }else {            System.out.println("API level 大于23");            //获得ConnectivityManager对象            ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);            //获取所有网络连接的信息            Network[] networks = connMgr.getAllNetworks();            //用于存放网络连接信息            StringBuilder sb = new StringBuilder();            //通过循环将网络信息逐个取出来            for (int i=0; i < networks.length; i++){                //获取ConnectivityManager对象对应的NetworkInfo对象                NetworkInfo networkInfo = connMgr.getNetworkInfo(networks[i]);                sb.append(networkInfo.getTypeName() + " connect is " + networkInfo.isConnected());            }            Toast.makeText(context, sb.toString(),Toast.LENGTH_SHORT).show();        }    }}

 在入口类注册监听