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如何在Android中使用Firebase以相反的顺序打印数据

[英]How can i print data in reverse order using firebase in android

i have a noticeboard activity to show to the notice. 我有一个布告栏活动,以显示该通知。 Now i want to print last notice at first position. 现在我想在第一个位置打印最后通知。 Means in reverse order. 意思相反。

            if (dataSnapshot.getValue() != null) {
                Iterable<DataSnapshot> snapshotIterator = dataSnapshot.getChildren();
                Iterator<DataSnapshot> iterator = snapshotIterator.iterator();

                while (iterator.hasNext()) {
                    //notificationCount++;
                    DataSnapshot snapshot = iterator.next();

If you are using FirebaseUI please use the following lines of code: 如果您使用的是FirebaseUI,请使用以下代码行:

LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
layoutManager.setReverseLayout(true);
layoutManager.setStackFromEnd(true);
recyclerView.setLayoutManager(layoutManager)

This is the answer. 这就是答案。

In this case, add all the elements from your snapshotIterator to a list and use then reverseOrder(Comparator cmp) according to the offical doc of Collections and in the end pass it to the adapter. 在这种情况下,将您的snapshotIterator中的所有元素添加到列表中,然后根据Collections的官方文档使用反向顺序(Comparator cmp),最后将其传递给适配器。 thanks to Mr. Alex Mamo 感谢Alex Mamo先生

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