public abstract class MyAdapter
     
       extends BaseAdapter {    private ArrayList
      
        mData;    private int mLayoutRes;           //布局id    public MyAdapter() {    }    public MyAdapter(ArrayList
       
         mData, int mLayoutRes) {        this.mData = mData;        this.mLayoutRes = mLayoutRes;    }    @Override    public int getCount() {        return mData != null ? mData.size() : 0;    }    @Override    public T getItem(int position) {        return mData.get(position);    }    @Override    public long getItemId(int position) {        return position;    }    @Override    public View getView(int position, View convertView, ViewGroup parent) {        ViewHolder holder = ViewHolder.bind(parent.getContext(), convertView, parent, mLayoutRes                , position);        bindView(holder, getItem(position));        return holder.getItemView();    }    public abstract void bindView(ViewHolder holder, T obj);    //添加一个元素    public void add(T data) {        if (mData == null) {            mData = new ArrayList<>();        }        mData.add(data);        notifyDataSetChanged();    }    //往特定位置，添加一个元素    public void add(int position, T data) {        if (mData == null) {            mData = new ArrayList<>();        }        mData.add(position, data);        notifyDataSetChanged();    }    public void remove(T data) {        if (mData != null) {            mData.remove(data);        }        notifyDataSetChanged();    }    public void remove(int position) {        if (mData != null) {            mData.remove(position);        }        notifyDataSetChanged();    }    public void clear() {        if (mData != null) {            mData.clear();        }        notifyDataSetChanged();    }    public static class ViewHolder {        private SparseArray
        
          mViews;   //存储ListView 的 item中的View        private View item;                  //存放convertView        private int position;               //游标        private Context context;            //Context上下文        //构造方法，完成相关初始化        private ViewHolder(Context context, ViewGroup parent, int layoutRes) {            mViews = new SparseArray<>();            this.context = context;            View convertView = LayoutInflater.from(context).inflate(layoutRes, parent, false);            convertView.setTag(this);            item = convertView;        }        //绑定ViewHolder与item        public static ViewHolder bind(Context context, View convertView, ViewGroup parent,                                      int layoutRes, int position) {            ViewHolder holder;            if (convertView == null) {                holder = new ViewHolder(context, parent, layoutRes);            } else {                holder = (ViewHolder) convertView.getTag();                holder.item = convertView;            }            holder.position = position;            return holder;        }        @SuppressWarnings("unchecked")        public 
         
           T getView(int id) {            T t = (T) mViews.get(id);            if (t == null) {                t = (T) item.findViewById(id);                mViews.put(id, t);            }            return t;        }        /**         * 获取当前条目         */        public View getItemView() {            return item;        }        /**         * 获取条目位置         */        public int getItemPosition() {            return position;        }        /**         * 设置文字         */        public ViewHolder setText(int id, CharSequence text) {            View view = getView(id);            if (view instanceof TextView) {                ((TextView) view).setText(text);            }            return this;        }        /**         * 设置图片         */        public ViewHolder setImageResource(int id, int drawableRes) {            View view = getView(id);            if (view instanceof ImageView) {                ((ImageView) view).setImageResource(drawableRes);            } else {                view.setBackgroundResource(drawableRes);            }            return this;        }        /**         * 设置点击监听         */        public ViewHolder setOnClickListener(int id, View.OnClickListener listener) {            getView(id).setOnClickListener(listener);            return this;        }        /**         * 设置可见         */        public ViewHolder setVisibility(int id, int visible) {            getView(id).setVisibility(visible);            return this;        }        /**         * 设置标签         */        public ViewHolder setTag(int id, Object obj) {            getView(id).setTag(obj);            return this;        }        //其他方法可自行扩展    }}