解决方法一:
$user = $user->toArray();$user1['createTime'] = $user['created_at'];
解决方法二:
$user1['createTime'] = $user->created_at->format('Y-m-d H:i:s');
解决方法三:
$user1['createTime'] = date('Y-m-d H:i:s', $user->created_at->timestamp);