mvp+分类(Fragment)

//主布局

          android:id="@+id/recycler"
         android:layout_width="100dp"
         android:layout_height="match_parent">
            android:id="@+id/classify_expand"
        android:layout_width="match_parent"

        android:layout_height="match_parent">

//左边数据布局

        android:id="@+id/classify_recycler_textview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:textSize="20dp"
        android:text="text"

        android:gravity="center"/>

//二级列表里套一个RecyclerView布局

        android:id="@+id/classify_expand_child_recycler"
        android:layout_width="match_parent"

        android:layout_height="match_parent">

//二级列表第一级

        android:id="@+id/classify_expand_parent_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="父布局"

        android:textSize="26dp"/>

//二级列表第二级

        android:id="@+id/classify_expand_child_recycler_image"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:src="@mipmap/ic_launcher"
        android:layout_gravity="center"
        android:layout_marginTop="10dp"/>
            android:id="@+id/classify_expand_child_recycler_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="text"
        android:textSize="26dp"
        android:layout_marginTop="10dp"/>

//M层(需要两个bean类)

public class ClassifyModel {
    public void loginleft(int cid,final ModelView modelView){
        String url="https://www.zhaoapi.cn/product/getCatagory";
        OkhtttpUtils.getInstance().doGet(url, new OkhtttpUtils.OkCallback() {
            @Override
            public void onFailure(Exception e) {

            }

            @Override
            public void onResponse(String json) {
                ClassifyLeftBean classifyLeftBean = new Gson().fromJson(json, ClassifyLeftBean.class);
                String code = classifyLeftBean.getCode();
                if ("0".equalsIgnoreCase(code)){
                    if (modelView!=null){
                        modelView.onSuccess(classifyLeftBean);
                    }
                }else {
                    if (modelView!=null){
                        modelView.onFailure("失败");
                    }
                }
            }
        });
        String u="https://www.zhaoapi.cn/product/getProductCatagory";
        Map map=new HashMap<>();
        map.put("cid",cid+"");
        OkhtttpUtils.getInstance().doPost(u, map, new OkhtttpUtils.OkCallback() {
            @Override
            public void onFailure(Exception e) {

            }

            @Override
            public void onResponse(String json) {
                ClassifyRightBean classifyRightBean = new Gson().fromJson(json, ClassifyRightBean.class);
                String code = classifyRightBean.getCode();
                if ("0".equalsIgnoreCase(code)){
                    if (modelView!=null){
                        modelView.onSuccess2(classifyRightBean);
                    }
                }else {
                    if (modelView!=null){
                        modelView.onFailure2("失败");
                    }
                }
            }
        });
    }
    public interface ModelView{
        void onSuccess(ClassifyLeftBean classifyLeftBean);
        void onFailure(String error);

        void onSuccess2(ClassifyRightBean classifyRightBean);
        void onFailure2(String error);
    }
}

//P层

public class ClassifyPresenter extends BasePresenter{

    private ClassifyModel classifyModel;

    public ClassifyPresenter(ClassifyView view) {
        super(view);
    }

    @Override
    protected void initModel() {
        classifyModel = new ClassifyModel();
    }
    public void loginleft(int cid){
        classifyModel.loginleft(cid,new ClassifyModel.ModelView() {
            @Override
            public void onSuccess(ClassifyLeftBean classifyLeftBean) {
                if (view!=null){
                    view.onClassifySuccess(classifyLeftBean);
                }
            }

            @Override
            public void onFailure(String error) {
                if (view!=null){
                    view.onClassifyFailure(error);
                }
            }

            @Override
            public void onSuccess2(ClassifyRightBean classifyRightBean) {
                if (view!=null){
                    view.onClassifySuccess2(classifyRightBean);
                }
            }

            @Override
            public void onFailure2(String error) {
                if (view!=null){
                    view.onClassifyFailure2(error);
                }
            }
        });
    }
}

//V层

public class ClassifyFragment extends BaseFragment implements ClassifyView{
    private List list=new ArrayList<>();
    private RecyclerView recyclerView;
    private MyRecyclerAdapter myRecyclerAdapter;
    private int cid=1;
    private MyExpandAdapter myExpandAdapter;
    private ExpandableListView expandableListView;

    @Override
    protected void initListener() {

    }

    @Override
    protected void initDatas() {
        presenter.loginleft(cid);
    }

    @Override
    protected void initViews() {
        recyclerView = getView().findViewById(R.id.recycler);
        expandableListView = getView().findViewById(R.id.classify_expand);
    }

    @Override
    protected ClassifyPresenter providePresenter() {
        return new ClassifyPresenter(this);
    }

    @Override
    protected int provideLayoutId() {
        return R.layout.activity_classify_fragment;
    }

    @Override
    public void onClassifySuccess(ClassifyLeftBean classifyLeftBean) {
        List data = classifyLeftBean.getData();
        list.addAll(data);
        myRecyclerAdapter = new MyRecyclerAdapter(list);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.setAdapter(myRecyclerAdapter);
        myRecyclerAdapter.setOnClassifyClickListance(new MyRecyclerAdapter.OnClassifyClickListance() {
            @Override
            public void onClassifyClick(int cid) {
                ++cid;
                presenter.loginleft(cid);
            }
        });
    }

    @Override
    public void onClassifyFailure(String error) {

    }

    @Override
    public void onClassifySuccess2(ClassifyRightBean classifyRightBean) {
        List data = classifyRightBean.getData();
        myExpandAdapter = new MyExpandAdapter(data, getContext());
        expandableListView.setAdapter(myExpandAdapter);
        for (int i = 0; i < data.size(); i++) {
            expandableListView.expandGroup(i);
        }
    }

    @Override
    public void onClassifyFailure2(String error) {

    }

    @Override
    public Context context() {
        return getActivity();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }

}

//左边RecyclerView适配器

public class MyRecyclerAdapter extends RecyclerView.Adapter{
    private List list;

    public MyRecyclerAdapter(List list) {
        this.list = list;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.classify_recycler_item, parent, false);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, final int position) {
        holder.textView.setText(list.get(position).getName());
        holder.textView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int cid = list.get(position).getCid();
                onClassifyClickListance.onClassifyClick(cid);
            }
        });
    }

    @Override
    public int getItemCount() {
        return list==null?0:list.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder{

        private final TextView textView;

        public MyViewHolder(View itemView) {
            super(itemView);
            textView = itemView.findViewById(R.id.classify_recycler_textview);
        }
    }
    OnClassifyClickListance onClassifyClickListance;
    public void setOnClassifyClickListance(OnClassifyClickListance onClassifyClickListance){
        this.onClassifyClickListance=onClassifyClickListance;
    }
    public interface OnClassifyClickListance{
        void onClassifyClick(int cid);
    }
}

//二级列表里的RecyclerView适配器

public class MyChildRecyclerAdapter extends RecyclerView.Adapter{
    private List list;
    private Context context;

    public MyChildRecyclerAdapter(List list, Context context) {
        this.list = list;
        this.context = context;
    }

    @NonNull
    @Override
    public IViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.classify_child_item_recycler, parent, false);
        return new IViewHolder(view);
    }

    @Override
    public int getItemCount() {
        return list==null?0:list.size();
    }

    @Override
    public void onBindViewHolder(@NonNull IViewHolder holder, int position) {
        String icon = list.get(position).getIcon();
        ImageLoader.getInstance().displayImage(icon,holder.imageView, MyApp.getOptions());
        holder.textView.setText(list.get(position).getName());
    }

    public class IViewHolder extends RecyclerView.ViewHolder{

        private final TextView textView;
        private final ImageView imageView;

        public IViewHolder(View itemView) {
            super(itemView);
            imageView = itemView.findViewById(R.id.classify_expand_child_recycler_image);
            textView = itemView.findViewById(R.id.classify_expand_child_recycler_text);
        }
    }
}

//二级列表适配器

public class MyExpandAdapter extends BaseExpandableListAdapter {
    private List list;
    private Context context;
    private MyChildRecyclerAdapter childRecyclerAdapter;

    public MyExpandAdapter(List list, Context context) {
        this.list = list;
        this.context = context;
    }

    @Override
    public int getGroupCount() {
        return list == null ? 0 : list.size();
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return 1;
    }

    @Override
    public Object getGroup(int groupPosition) {
        return null;
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return null;
    }

    @Override
    public long getGroupId(int groupPosition) {
        return 0;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return 0;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        ParentViewHolder parentViewHolder;
        if (convertView == null) {
            convertView = View.inflate(context, R.layout.classify_expand_parent, null);
            parentViewHolder = new ParentViewHolder(convertView);
            convertView.setTag(parentViewHolder);
        } else {
            parentViewHolder = (ParentViewHolder) convertView.getTag();
        }
        parentViewHolder.classifyExpandParentName.setText(list.get(groupPosition).getName());
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        ChildViewHolder childViewHolder;
        if (convertView == null) {
            convertView = View.inflate(context, R.layout.classify_expand_child, null);
            childViewHolder=new ChildViewHolder(convertView);
            convertView.setTag(childViewHolder);
        }else {
            childViewHolder=(ChildViewHolder)convertView.getTag();
        }
        List listBeans = this.list.get(groupPosition).getList();
        GridLayoutManager gridLayoutManager = new GridLayoutManager(parent.getContext(), 2);
        childRecyclerAdapter=new MyChildRecyclerAdapter(listBeans,parent.getContext());
        childViewHolder.classifyExpandChildRecycler.setLayoutManager(gridLayoutManager);
        childViewHolder.classifyExpandChildRecycler.setAdapter(childRecyclerAdapter);
        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return false;
    }

    static class ParentViewHolder {
        @BindView(R.id.classify_expand_parent_name)
        TextView classifyExpandParentName;

        ParentViewHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }

    static class ChildViewHolder {
        @BindView(R.id.classify_expand_child_recycler)
        RecyclerView classifyExpandChildRecycler;

        ChildViewHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }
}

//V层接口

public interface ClassifyView extends IView{
    void onClassifySuccess(ClassifyLeftBean classifyLeftBean);
    void onClassifyFailure(String error);

    void onClassifySuccess2(ClassifyRightBean classifyRightBean);
    void onClassifyFailure2(String error);
}