public class SelectLeaderAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private Context context;
    private List<String> mList;
    private boolean mIsSelectable;
    private SparseBooleanArray mSelectedPositions;

    public SelectLeaderAdapter(Context context, List<String> list) {
        this.context = context;
        this.mList = list;
    }

    //更新adpter的數據和選擇狀態
    public void updateDataSet(ArrayList<String> list) {
        this.mList = list;
        mSelectedPositions = new SparseBooleanArray();
    }


    //獲得選中條目的結果
    public ArrayList<String> getSelectedItem() {
        ArrayList<String> selectList = new ArrayList<>();
        for (int i = 0; i < mList.size(); i++) {
            if (isItemChecked(i)) {
                selectList.add(mList.get(i));
            }
        }
        return selectList;
    }

    //設置給定位置條目的選擇狀態
    private void setItemChecked(int position, boolean isChecked) {
        if (mSelectedPositions == null) {
            mSelectedPositions = new SparseBooleanArray();
        }
        mSelectedPositions.put(position, isChecked);
    }

    //根據位置判斷條目是否選中
    private boolean isItemChecked(int position) {
        if (mSelectedPositions != null) {
            return mSelectedPositions.get(position);
        }
        return false;
    }

    //根據位置判斷條目是否可選
    private boolean isSelectable() {
        return mIsSelectable;
    }

    //設置給定位置條目的可選與否的狀態
    private void setSelectable(boolean selectable) {
        mIsSelectable = selectable;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        View itemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_selectleaderauther_lv, viewGroup, false);
        return new ListItemViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
        //設置條目狀態
        ((ListItemViewHolder) holder).name.setText(mList.get(position));
        //判斷是否選中
        boolean itemChecked = isItemChecked(position);
        if (itemChecked) {
            ((ListItemViewHolder) holder).name.setTextColor(context.getResources().getColor(R.color.bg_White));
            ((ListItemViewHolder) holder).name.setBackgroundColor(context.getResources().getColor(R.color.themeColor));
        } else {
            ((ListItemViewHolder) holder).name.setBackgroundColor(context.getResources().getColor(R.color.green3));
            ((ListItemViewHolder) holder).name.setTextColor(context.getResources().getColor(R.color.green1));
        }
        ((ListItemViewHolder) holder).checkBox.setChecked(itemChecked);

        //checkBox的監聽
        ((ListItemViewHolder) holder).checkBox.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (isItemChecked(position)) {
                    setItemChecked(position, false);
                } else {
                    setItemChecked(position, true);
                }
            }
        });

        //條目view的監聽
        ((ListItemViewHolder) holder).itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (isItemChecked(position)) {
                    setItemChecked(position, false);
                } else {
                    setItemChecked(position, true);
                }
                notifyItemChanged(position);
            }
        });
    }


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

    public class ListItemViewHolder extends RecyclerView.ViewHolder {
        CheckBox checkBox;
        TextView name;

        ListItemViewHolder(View view) {
            super(view);
            this.name = (TextView) view.findViewById(R.id.selectfriends_username);
            this.checkBox = (CheckBox) view.findViewById(R.id.cb_selectfriends);

        }
    }
}