随机排列ArrayList

Question

我有两个RecyclerView和一个称为collections的 ArrayList ，我试图改组此ArrayList并获取其中的12个项目。

@Override
protected void onPostExecute(List<CollectionsModel> collections) {
    super.onPostExecute(collections);
    if (isAdded() && getActivity() != null) {
        setAdapterForRecyclerView(collections);
         setAdapterForRecyclerViewBestCollections(shuffleCollection(collections));
    }
}

随机播放方法：

public List<CollectionsModel> shuffleCollection(List<CollectionsModel> collectionsModelList) {
    java.util.Collections.shuffle(collectionsModelList);
    return collectionsModelList;
}

RecyclerView 1的适配器方法：

private void setAdapterForRecyclerViewBestCollections(List<CollectionsModel> collectionHelper) {
    for (int i = 0; i < 12; i++) {
        arrayListCollections.add(collectionHelper.get(i));
    }
    /*rest of code*/
}

RecyclerView 2的适配器方法：

private void setAdapterForRecyclerView(final List<CollectionsModel> wlls) {
    if (myAdapter == null) {
        myAdapter = new MyAdapterCollection(wlls, getActivity(), new RecyclerViewClickListener() {
            @Override
            public void onClick(View view, Wallpaper wallpaper) {

            }

            @Override
            public void onClick(View view, CollectionsModel collectionsModel) {

            }
        }, R.layout.collection_item);
        recyclerView.setAdapter(myAdapter);
    } else {
        int position = myAdapter.getItemCount();
        myAdapter.getItems().addAll(wlls);
        myAdapter.notifyItemRangeInserted(position, position);
    }
}

我的问题：

当我运行该应用程序时，我看到RecyclerView 1和RecyclerView 2都是随机的（顺序相同）。

我想要的是 ：

我想在RecyclerView 1和正常订单RecyclerView 2中看到随机物品的顺序

Answer 1

首先，您setAdapterForRecyclerView(collections);列表对象传递给setAdapterForRecyclerView(collections);

之后，您setAdapterForRecyclerViewBestCollections(shuffleCollection(collections));同一列表对象传递给setAdapterForRecyclerViewBestCollections(shuffleCollection(collections));

然后改组对象（在您使用同一对象的两种方法中，改组将同时反映到RecyclerView1和RecyclerView2

创建新的List对象，并在改组后返回该对象，以便您在RecyclerView1和RecyclerView2看到两个不同的顺序

public List<CollectionsModel> shuffleCollection(List<CollectionsModel> collectionsModelList) {
    List<CollectionsModel> shuff = new ArrayList<>(collectionsModelList);
    java.util.Collections.shuffle(shuff);
    return shuff;
}