如何改组RealmResults对象的内容 [英] How can I shuffle the contents of a RealmResults object

问题描述

我有一个RealmResults对象，该对象保存.where.findAll()查询的输出.我正在RecyclerView中显示此对象的内容，但是由于RealmResults对象的内容是静态的，因此每次打开RecyclerView时，它都会显示相同的记录集.我想随机播放(随机化)RealmResults的内容，以便可以在RecyclerView中显示RealmResults中的不同值.请提出一些我可以执行相同操作的可能方法.

I have a RealmResults object which holds output of a .where.findAll() query. I am showing contents of this object in a RecyclerView, but since the contents of the RealmResults object are static, it shows same set of records evertime the RecyclerView is opened. I want to shuffle (randomize) the contents of RealmResults so that I can show different values that are in the RealmResults in my RecyclerView. Please suggest some possible ways in which I can perform the same.

推荐答案

您不应该对列表本身进行随机化，而应该对列表(索引)的访问进行随机化.

You should not randomize the list itself, you should randomize your access of it (the indices).

构建一个包含[0, n-1]

List<Integer> indices = new ArrayList<>(realmResults.size());
for(int i = 0; i < realmResults.size(); i++) {
    indices.add(i);
}

随机播放

Collections.shuffle(indices);

然后，当您选择视图持有者数据时，将为具有索引的随机位置的索引域结果

Then when you pick the view holder data, index realm results with indexed random position

public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    if(holder instanceof YourHolder) {
        YourHolder yourHolder = (YourHolder) holder;
        RealmData realmData = realmResults.get(indices.get(position));
        //init data for your holder
    }
}

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