可以以相反的顺序遍历Firebase节点的子节点吗？-PossibletotraversethechildrenofaFirebasenodeinreverseorder?

9  

It sounds like what you want is a "reverse()" query similar to how "limit()" works now. Firebase can't do this yet, but we're planning to add it.

听起来你想要的是一个类似于“limit（）”现在如何工作的“reverse（）”查询。 Firebase还不能这样做，但我们计划添加它。

Depending on your use case, it might be pretty simple for you to get around this though. If, for instance, you're using Firebase's sorting to keep a list in order that is being displayed to the user, you could simply modify the display logic to render things backward (prepend items instead of append for instance). If you're querying to select a window of data out of a large set of children (say, to get the first 10 items out of a long list), the sort order shouldn't be important -- your start and end points for the query will remain the same except they'll be reversed.

根据您的使用情况，您可能很容易解决这个问题。例如，如果您使用Firebase的排序按顺序保存列表，则可以简单地修改显示逻辑以向后渲染事物（例如，前置项而不是附加项）。如果您要查询从大量子项中选择一个数据窗口（例如，从长列表中获取前10个项目），排序顺序应该不重要 - 您的起点和终点查询将保持不变，但它们将被颠倒。

0  

Can you use limitToLast() and sort the result set yourself? I know this kind of thing works if you happen to be using Angular, where items is a Firebase array object on the $scope;

你可以使用limitToLast（）并自己对结果集进行排序吗？我知道如果您碰巧使用Angular，这种事情是有效的，其中items是$ scope上的Firebase数组对象;

 {{ item.fildName }}