写了一个listview，每个item里面有一个switchButton，每个item绑定一个Light类，打开开关Light类的状态属性会改变。

但是发现listview拉到底后(顶部的item移出界面)，再拉回到顶部，switchButton的状态被初始化了，这该如何解决？

private class LightsDataAdapter extends BaseAdapter {
    //定义操作的灯
    public Light light;
    public List<Light> lightsList;
    //用于把布局文件转化为View对象
    private LayoutInflater layoutInflater;

    public LightsDataAdapter(Context context, List<Light> lightsList) {
        this.lightsList = lightsList;
        layoutInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return lightsList.size();
    }

    @Override
    public Object getItem(int position) {
        return lightsList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }


    public class ViewHolder {
        RelativeLayout relativeLayout;
        TextView tvName;
        Switch swBtn;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup group) {
        View viewItem = null;
        ViewHolder viewHolder = null;
        if (convertView == null) {
            viewItem = layoutInflater.inflate(R.layout.listview_item_light, null);
            viewHolder = new ViewHolder();
            viewHolder.relativeLayout = viewItem.findViewById(R.id.list_item);
            viewHolder.tvName = viewItem
                    .findViewById(R.id.tvName);
            viewHolder.swBtn = viewItem.findViewById(R.id.btn_sw);
            viewItem.setTag(viewHolder);
        } else {
            viewItem = convertView;
            viewHolder = (ViewHolder) viewItem.getTag();
        }

        final Light le = lightsList.get(position);
        if (le.getType() == "white" || le.getType() == "smart") {
            if (le.getState() == true) {
                addLightView(le.getName());
                viewHolder.relativeLayout.setBackgroundColor(Color.argb(255, 255, 255, 255));
                viewHolder.tvName.setTextColor(Color.parseColor("#000000"));
            } else {
                removeLightView(le.getName());
                viewHolder.relativeLayout.setBackgroundColor(getColor(R.color.lightOff));
                viewHolder.tvName.setTextColor(Color.parseColor("#ffffff"));
            }
        } else {
            if (le.getState() == true) {
                addRGBLightView(le.getName(),Color.argb(255, ((RgbLight) le).getrValue(), ((RgbLight) le).getgValue(), ((RgbLight) le).getbValue()));
                viewHolder.relativeLayout.setBackgroundColor(Color.argb(255, ((RgbLight) le).getrValue(), ((RgbLight) le).getgValue(), ((RgbLight) le).getbValue()));
                viewHolder.tvName.setTextColor(Color.parseColor("#000000"));
            } else {
                removeRGBLightView(le.getName());
                viewHolder.relativeLayout.setBackgroundColor(getColor(R.color.lightOff));
                viewHolder.tvName.setTextColor(Color.parseColor("#ffffff"));
            }
        }
        viewHolder.tvName.setText(le.getName());
        viewHolder.swBtn.setChecked(le.getState());
        final ViewHolder finalViewHolder = viewHolder;
        if (le.getType() == "white") {
            viewHolder.relativeLayout.setEnabled(false);
        } else {
            viewHolder.relativeLayout.setEnabled(true);
        }
        viewHolder.relativeLayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.i("11", le.getName() + finalViewHolder.tvName.getText());
                light = setColoCycle(le.getName(), (Color.rgb(((RgbLight) le).getrValue(), ((RgbLight) le).getgValue(), ((RgbLight) le).getbValue())), le);

            }
        });
        viewHolder.relativeLayout.setOnTouchListener(onTouchListener);
        viewHolder.swBtn.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (le.getType() == "white" || le.getType() == "smart") {
                    if (isChecked == true) {
                        le.setState(true);
                        addLightView(le.getName());
                        finalViewHolder.relativeLayout.setBackgroundColor(Color.argb(255, 255, 255, 255));
                        finalViewHolder.tvName.setTextColor(Color.parseColor("#000000"));
                    } else {
                        le.setState(false);
                        removeLightView(le.getName());
                        finalViewHolder.relativeLayout.setBackgroundColor(getColor(R.color.lightOff));
                        finalViewHolder.tvName.setTextColor(Color.parseColor("#ffffff"));
                    }
                } else {
                    if (isChecked == true) {
                        le.setState(true);
                        addRGBLightView(le.getName(),Color.argb(255, ((RgbLight) le).getrValue(), ((RgbLight) le).getgValue(), ((RgbLight) le).getbValue()));
                        finalViewHolder.relativeLayout.setBackgroundColor(Color.argb(255, ((RgbLight) le).getrValue(), ((RgbLight) le).getgValue(), ((RgbLight) le).getbValue()));
                        finalViewHolder.tvName.setTextColor(Color.parseColor("#000000"));
                    } else {
                        le.setState(false);
                        removeRGBLightView(le.getName());
                        finalViewHolder.relativeLayout.setBackgroundColor(getColor(R.color.lightOff));
                        finalViewHolder.tvName.setTextColor(Color.parseColor("#ffffff"));
                    }
                }
            }

        });
        return viewItem;
    }
}