如何从android中的firebase数据库中获取随机对象？ [英] How to get a random object from firebase database in android?

问题描述

我正在开发一个Android应用，我需要从一个孩子的firebase中获取一个随机对象？如何在java中做到这一点？

I am working on an Android app, where I need to get a random object from firebase from a child? How to do it in java?

推荐答案

这就是我要做的，假设我有一个有n个对象的孩子：

This is how I would do it, assuming I had a child with n objects:

如果我不知道n的值，我会首先在我的监听器中执行此操作以获取对象的总数：

If I didn't know how the value of n, I would first do this in my listener to get the total number of objects:

                long n = dataSnapshot.getChildrenCount();

然后我会生成一个0到n之间的随机整数i。如果你不知道如何做到这一点，谷歌吧。

Then I would generate a random integer, i, between 0 and n. If you don't know how to do this, Google it.

最后，我会从孩子那里得到第i项：

Finally, I would get the ith item from the child:

            final ArrayList<MyObject> objects = new ArrayList<>();
            for (DataSnapshot child : children) {
                MyObject object = child.getValue(MyObject.class);
                objects.add(object);
            }
            MyObject objectToUse = objects.get(i);

MyObject显然应该是你正在使用的任何类。

"MyObject" should obviously be whatever class you're using.

我错过了什么吗？有一个更好的方法吗？我对Android很新，对Firebase来说还是新手，所以我要说的话就是用大量的盐哈哈。

Am I missing something? Is there a better way to do this? I'm pretty new to Android and very new to Firebase so take what I have to say with a big grain of salt haha.

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