Android网络连接监听

public class NetStateReceiver extends BroadcastReceiver {
    private Handler handler;

    public NetStateReceiver(Handler handler) {
        this.handler = handler;
    }

    @Override
    public void onReceive(Context context, Intent arg1) {
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo gprs = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
        NetworkInfo wifi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        if (!gprs.isConnected() && !wifi.isConnected()) {
            System.out.println("网络已断开");
            SysUtils.sendHandlerMsg(handler, SysConstant.MSG_NET_CONN_DISS);
        }

        if (gprs.isConnected() || wifi.isConnected()) {
            System.out.println("网络已连接");
            SysUtils.sendHandlerMsg(handler, SysConstant.MSG_NET_CONN_CONN);
        }
    }

}

public class MyActivity extends Activity {
    /** 网络连接状态 true:连接;false:断开 */
    public boolean netState = false;

    private NetStateReceiver receiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        int device = GpdService.DEVICE_TYPE_SCANNER;// 一维或二维条码扫描头
        MyGpdUtils.startGpdService(this, device);

        // 注册广播接收者
        receiver = new NetStateReceiver(handler);
        IntentFilter filter = new IntentFilter();
        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(receiver, filter);
        receiver.onReceive(this, null);
    }

    Handler handler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            switch (msg.what) {
            case SysConstant.MSG_NET_CONN_DISS:// 网络断开
                MyGpdUtils.playSound("网络连接已断开");
                netState = false;
                break;
            case SysConstant.MSG_NET_CONN_CONN:// 网络连接
                // MyGpdUtils.playSound("网络已连接");
                netState = true;
                break;
            }
        };
    };

}

                /** 网络连接消息 */
    public static final int MSG_NET_CONN_DISS = 222;
    public static final int MSG_NET_CONN_CONN = 223;