如何检查后台服务（Android的Service类）是否正在运行？

private boolean isServiceRunning() {
    ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
    for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
        if ("com.example.MyService".equals(service.service.getClassName())) {
            return true;
        }
    }
    return false;
}