概述

Android开发左右联动列表，仿照美团外卖点餐时，左右列表可以联动。

详细

Android开发仿美团购物左右联动列表

概述

左右联动列表是仿照美团外卖点餐时，左右列表可以联动。比如右边列表会有小项对应左边的，滑动时会置顶，滑动到下一个小项时，置顶会切换，并且左边列表的项也相应切换。同理，左边项的点击，右边的列表也会跟着滚动，对应的小项也会置顶。

详细

一、运行效果如下：

二、实现过程：

1、右边列表adapter

 

    public class RightAdapter extends RecyclerView.Adapter {
        private ArrayList<FoodBean> mList;
        private LayoutInflater mLayoutInflater;
        public RightAdapter(LayoutInflater layoutInflater, ArrayList<FoodBean> list) {
            this.mList = list;
            mLayoutInflater = layoutInflater;
        }
        private FoodBean getItem(int position) {
            return mList.get(position);
        }
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            return new RightViewHolder(
                    mLayoutInflater.inflate(R.layout.listitem_right_content, parent, false));
        }
        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
            FoodBean target = getItem(position);
            if (holder instanceof RightViewHolder) {
                ((RightViewHolder) holder).bindBean(target);
            } else {
                throw new IllegalStateException("Illegal state Exception onBindviewHolder");
            }
        }
        @Override
        public int getItemCount() {
            return mList.size();
        }
        private class RightViewHolder extends RecyclerView.ViewHolder {
            private TextView tvFoodTitle;
            private ImageView ivFood;
            RightViewHolder(View itemView) {
                super(itemView);
                tvFoodTitle = (TextView) itemView.findViewById(R.id.tv_food_title);
                ivFood = (ImageView) itemView.findViewById(R.id.iv_food);
            }
            void bindBean(final FoodBean bean) {
                tvFoodTitle.setText(bean.getFoodTitle());
                ivFood.setImageResource(bean.getImageResId());
            }
        }
    }  

其中FoodBean.class

    public class FoodBean {
        private int imageResId;
        private String foodTitle;
        //这是每小项的标题，用来滑动置顶用
        private String itemTitle;
        public FoodBean(int imageResId, String foodTitle,String itemTitle) {
            this.imageResId = imageResId;
            this.foodTitle = foodTitle;
            this.itemTitle = itemTitle;
        }
        public FoodBean(int imageResId, String foodTitle) {
            this.imageResId = imageResId;
            this.foodTitle = foodTitle;
        }
        public String getItemTitle() {
            return itemTitle;
        }
        public void setItemTitle(String itemTitle) {
            this.itemTitle = itemTitle;
        }
        public int getImageResId() {
            return imageResId;
        }
        public void setImageResId(int imageResId) {
            this.imageResId = imageResId;
        }
        public String getFoodTitle() {
            return foodTitle;
        }
        public void setFoodTitle(String foodTitle) {
            this.foodTitle = foodTitle;
        }
    }

2、左边adapter

    public class LeftAdapter extends RecyclerView.Adapter<LeftAdapter.LeftViewHolder> {
        private ArrayList<LeftBean> mList;
        private OnItemClickListener onItemClickListener;
        public LeftAdapter( ArrayList<LeftBean> list) {
            this.mList = list;
        }
        public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
            this.onItemClickListener = onItemClickListener;
        }
        private LeftBean getItem(int position) {
            return mList.get(position);
        }
        @Override
        public LeftViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view= LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.listitem_left_content,parent,false);
            return new LeftViewHolder(view);
        }
        @Override
        public void onBindViewHolder(LeftViewHolder holder, int position) {
            LeftBean target = getItem(position);
            holder.tvTitle.setText(target.getTitle());
            if (target.isSelect()){
                holder.itemView.setBackgroundColor(ContextCompat.getColor(holder.itemView.getContext(), R.color.white));
            } else {
                holder.itemView.setBackgroundColor(ContextCompat.getColor(holder.itemView.getContext(), R.color.c_aaa));
            }
            //绑定监听事件
            holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Log.v("onClick",position+"\t");
                    if (onItemClickListener != null){
                        onItemClickListener.onItemClicked(getItem(position).getRightPosition());
                    }
                    for (LeftBean bean:mList){
                        bean.setSelect(false);
                    }
                    getItem(position).setSelect(true);
                    notifyDataSetChanged();
                }
            });
        }
        @Override
        public int getItemCount() {
            return mList.size();
        }
        public static class LeftViewHolder extends RecyclerView.ViewHolder {
            private final TextView tvTitle;
            //private View cl_left_item;
            LeftViewHolder(View itemView) {
                super(itemView);
                tvTitle = (TextView) itemView.findViewById(R.id.tv_title);
            }
        }
        interface OnItemClickListener {
            void onItemClicked(int rightPosition );
        }
        public void setCurrentPosition(int rightPosition){
            for (LeftBean bean:mList){
                if (bean.getRightPosition() == rightPosition){
                    bean.setSelect(true);
                } else {
                    bean.setSelect(false);
                }
            }
            notifyDataSetChanged();
        }
        public String getCurrentTitle(){
            String currentTitle = "";
            for (LeftBean bean:mList){
                if (bean.isSelect()){
                    currentTitle = bean.getTitle();
                    break;
                }
            }
            return currentTitle;
        }
    }  

主要处理点击左边项目的选中状态，并将右边的小项的position回调出去给右边列表使用
其中LeftBean.class

    public class LeftBean {
        //记录右边列表置顶项所在的item的位置
        private int rightPosition;
        private String title;
        //设置是否选中，改变背景色
        private boolean isSelect;
        public LeftBean(int rightPosition, String title) {
            this.rightPosition = rightPosition;
            this.title = title;
        }
        public boolean isSelect() {
            return isSelect;
        }
        public void setSelect(boolean select) {
            isSelect = select;
        }
        public int getRightPosition() {
            return rightPosition;
        }
        public void setRightPosition(int rightPosition) {
            this.rightPosition = rightPosition;
        }
        public String getTitle() {
            return title;
        }
        public void setTitle(String title) {
            this.title = title;
        }
    }  

三、项目结构图