这里实现的是一个三级列表效果，可展开和收起。
三个实体类ExpandItem、Expand1Item和Expand2Item，均要继承AbstractExpandableItem，实现接口MultiItemEntity.
public class ExpandItem extends AbstractExpandableItem<Expand1Item> implements MultiItemEntity { private String title; public ExpandItem(String title){ this.title = title; } @Override public int getLevel() { return 0; } @Override public int getItemType() { return QuickExpandableAdapter.TYPE_LEVEL_0; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } } public class Expand1Item extends AbstractExpandableItem<Expand2Item> implements MultiItemEntity { private String title; public Expand1Item(String title){ this.title = title; } @Override public int getLevel() { return 1; } @Override public int getItemType() { return QuickExpandableAdapter.TYPE_LEVEL_1; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } } public class Expand2Item implements MultiItemEntity { private String title; public Expand2Item(String title){ this.title = title; } @Override public int getItemType() { return QuickExpandableAdapter.TYPE_LEVEL_2; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } }
一个适配器QuickExpandableAdapter，继承自BaseMultiItemQuickAdapter。
public class QuickExpandableAdapter extends BaseMultiItemQuickAdapter<MultiItemEntity, BaseViewHolder> { public static final int TYPE_LEVEL_0 = 0; public static final int TYPE_LEVEL_1 = 1; public static final int TYPE_LEVEL_2 = 2; /** * Same as QuickAdapter#QuickAdapter(Context,int) but with * some initialization data. * * @param data A new list is created out of this one to avoid mutable list */ public QuickExpandableAdapter(List<MultiItemEntity> data) { super(data); addItemType(TYPE_LEVEL_0, R.layout.view_expand_0); addItemType(TYPE_LEVEL_1, R.layout.view_expand_1); addItemType(TYPE_LEVEL_2, R.layout.view_expand_2); } @Override protected void convert(final BaseViewHolder helper, MultiItemEntity item) { switch (helper.getItemViewType()){ case TYPE_LEVEL_0: final ExpandItem item0 = (ExpandItem) item; helper.setText(R.id.expand_list_item0_tv,item0.getTitle()); helper.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int pos = helper.getAdapterPosition(); if (item0.isExpanded()){ collapse(pos); ToastUtils.showShortToast("收起：" + item0.getTitle()); }else { expand(pos); ToastUtils.showShortToast("展开：" + item0.getTitle()); } } }); break; case TYPE_LEVEL_1: final Expand1Item item1 = (Expand1Item) item; helper.setText(R.id.expand_list_item1_tv,item1.getTitle()); helper.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int pos = helper.getAdapterPosition(); if (item1.isExpanded()){ collapse(pos, false); ToastUtils.showShortToast("收起：" + item1.getTitle()); } else { expand(pos, false); ToastUtils.showShortToast("展开：" + item1.getTitle()); } } }); break; case TYPE_LEVEL_2: final Expand2Item item2 = (Expand2Item) item; helper.setText(R.id.expand_list_item2_tv,item2.getTitle()); helper.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { ToastUtils.showShortToast("点击：" + item2.getTitle()); } }); break; } } }
实现类QuickExpandableActivity
public class QuickExpandableActivity extends BaseRecyclerViewActivity { private QuickExpandableAdapter expandableAdapter; @Override protected int getLayoutResId() { return super.getLayoutResId(); } @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); titleNameTv.setText("实现多级列表功能"); expandableAdapter = new QuickExpandableAdapter(getExpandListData(10)); expandableAdapter.openLoadAnimation(BaseQuickAdapter.SLIDEIN_RIGHT); recyclerView.setAdapter(expandableAdapter); expandableAdapter.expandAll(0,true); } @Override protected void onRefreshComplete() { expandableAdapter.addData(0,getExpandListData(2)); recyclerView.scrollToPosition(0); } private List<MultiItemEntity> getExpandListData(int count) { int lvCount = count; int lv1Count = 3; int lv2Count = 5; List<MultiItemEntity> data = new ArrayList<>(); for (int i = 0; i < lvCount; i++) { ExpandItem item0 = new ExpandItem("一级列表标题" + i); for (int j = 0; j < lv1Count; j++) { Expand1Item item1 = new Expand1Item("二级列表标题" + j); for (int k = 0; k < lv2Count; k++) { item1.addSubItem(new Expand2Item("三级列表标题" + k)); } item0.addSubItem(item1); } data.add(item0); } return data; } } 效果图如下：