二级联动（分类联动）

activity布局

    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.activity.MainActivity">
    android:id="@+id/main_right"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_weight="2"
    >
            android:id="@+id/main_left"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        >

适配器布局 左

    android:orientation="vertical"
    android:id="@+id/left_adapater"
    android:layout_width="match_parent"
    android:layout_height="50dp">
    android:id="@+id/left_tv"
    android:layout_width="match_parent"
    android:layout_height="50dp" />

右

    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="50dp">
    android:id="@+id/right_tv"
    android:layout_width="match_parent"
    android:layout_height="50dp" />

适配器 右

public class RightAdapater extends BaseQuickAdapter {
    public RightAdapater(int layoutResId, @Nullable List data) {
        super(layoutResId, data);
    }

    @Override
    protected void convert(BaseViewHolder helper, TwoBean.ResultBean item) {
        helper.setText(R.id.right_tv,item.getName());

    }
}

左

public class LeftAdapater extends BaseQuickAdapter {

    private double mPosition;
    public LeftAdapater(int layoutResId, @Nullable List data) {
        super(layoutResId, data);
    }

    @Override
    protected void convert(BaseViewHolder helper, OneBean.ResultBean item) {
        helper.setText(R.id.left_tv,item.getName());
        View  view = helper.getView(R.id.left_adapater);
        if (mPosition!=helper.getAdapterPosition()){
            view.setBackgroundResource(R.color.colorAccent);
        }else {
            view.setBackgroundResource(0);
        }
    }

    public void setCurrentPosition(int Position) {
        mPosition=Position;
        notifyDataSetChanged();
    }
}
MVP

契约类

public interface HomeContract {
     public interface HomeModel{
         void HomeData(Context context,HomeBack homeBack);
         void HomeTwoData(String firstCategoryId,HomeTwoBack homeTwoBack);
         interface HomeBack{
             void getData(OneBean oneBean);
         }
         interface HomeTwoBack{
             void getTwoData(TwoBean twoBean);
         }
     }
     interface HomeView{
         void showData(OneBean oneBean);
         void showTwoData(TwoBean twoBean);
     }
     interface HomePresenter{
         void onAttachView();
         void onDetachView();
     }
}

M层

public class HomeModel implements HomeContract.HomeModel {

    private HttpUtils util;

    @Override
    public void HomeData(Context context, final HomeBack homeBack) {
        util = HttpUtils.getUtil();
        boolean work = util.NetWork(context);
        if (work){
            ApiService apiService = util.requestData(ApiService.class);
            Observable onedata = apiService.onedata();
            onedata.observeOn(AndroidSchedulers.mainThread())
                    .subscribeOn(Schedulers.io())
                    .subscribe(new Consumer() {
                        @Override
                        public void accept(OneBean oneBean) throws Exception {
                            homeBack.getData(oneBean);
                        }
                    });
        }else {
            Toast.makeText(context, "无网络连接", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void HomeTwoData(String firstCategoryId, final HomeTwoBack homeTwoBack) {

            ApiService apiService = util.requestData(ApiService.class);
            Observable twodata = apiService.twodata(firstCategoryId);
            twodata.observeOn(AndroidSchedulers.mainThread())
                    .subscribeOn(Schedulers.io())
                    .subscribe(new Consumer() {
                        @Override
                        public void accept(TwoBean twoBean) throws Exception {
                            homeTwoBack.getTwoData(twoBean);
                        }
                    });

    }
}

P层

public class HomePresenter extends BasePresenter {

    private final HomeModel model;

    public HomePresenter(){
        model = new HomeModel();
     }
     public void getData(Context context){
        model.HomeData(context, new HomeContract.HomeModel.HomeBack() {
            @Override
            public void getData(OneBean oneBean) {
                getView().showData(oneBean);
            }
        });
     }
     public void getTwoData( String firstCategoryId){
        model.HomeTwoData( firstCategoryId, new HomeContract.HomeModel.HomeTwoBack() {
            @Override
            public void getTwoData(TwoBean twoBean) {
                getView().showTwoData(twoBean);
            }
        });
     }
}

Activity代码

public class MainActivity extends BaseActivity> implements HomeContract.HomeView {

    @BindView(R.id.main_right)
    RecyclerView mainRight;
    @BindView(R.id.main_left)
    RecyclerView mainLeft;
    private RightAdapater rightAdapater;
    private LeftAdapater leftAdapater;
    private HttpUtils util;

    @Override
    protected void initData() {
presenter.getData(this);
    }

    @Override
    protected HomePresenter createPresenter() {
        return new HomePresenter<>();
    }

    @Override
    protected int getLayout() {
        return R.layout.activity_main;
    }

    @Override
    public void showData(final OneBean oneBean) {
        mainLeft.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false));
        leftAdapater = new LeftAdapater(R.layout.main_left, oneBean.getResult());
        mainLeft.setAdapter(leftAdapater);
        leftAdapater.setOnItemClickListener(new BaseQuickAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(BaseQuickAdapter adapter, View view, int position) {
                leftAdapater.setCurrentPosition(position);
                String id = oneBean.getResult().get(position).getId();
                presenter.getTwoData(id);
            }
        });
    }

    @Override
    public void showTwoData(TwoBean twoBean) {
        mainRight.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false));
        rightAdapater = new RightAdapater(R.layout.main_right, twoBean.getResult());
        mainRight.setAdapter(rightAdapater);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // TODO: add setContentView(...) invocation
        ButterKnife.bind(this);
    }

}

一个借口的联动
Activity

public class MainActivity extends AppCompatActivity {

    @BindView(R.id.rv_zuo)
    RecyclerView mRvZuo;
    @BindView(R.id.rv_you)
    RecyclerView mRvYou;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

        RetrofitUtil.getInstance().setRetrofitClass(new RetrofitUtil.RetrofitClass() {
            @Override
            public void getData(String resqonBody) {
                Gson gson = new Gson();
                final Bean bean = gson.fromJson(resqonBody, Bean.class);
                final List result = bean.getResult();

                LinearLayoutManager layoutManager = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.VERTICAL, false);
                mRvZuo.setLayoutManager(layoutManager);

                ZuoAdapter zuoAdapter = new ZuoAdapter(R.layout.zuo, result);
                mRvZuo.setAdapter(zuoAdapter);

                zuoAdapter.setOnItemClickListener(new BaseQuickAdapter.OnItemClickListener() {
                    @Override
                    public void onItemClick(BaseQuickAdapter adapter, View view, int position) {
                        List secondCategoryVo = result.get(position).getSecondCategoryVo();

                        GridLayoutManager gridLayoutManager = new GridLayoutManager(MainActivity.this, 2);
                        mRvYou.setLayoutManager(gridLayoutManager);

                        YouAdapter youAdapter = new YouAdapter(R.layout.you, secondCategoryVo);
                        mRvYou.setAdapter(youAdapter);
                    }
                });

            }
        });
    }
}

适配器

public class ZuoAdapter extends BaseQuickAdapter {
    public ZuoAdapter(int layoutResId, @Nullable List data) {
        super(layoutResId, data);
    }

    @Override
    protected void convert(BaseViewHolder helper, Bean.ResultBean item) {
        helper.setText(R.id.tv_zuo,item.getName());
    }
}