android listview 单选功能

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.TextView;
import com.ccvideo.R;
import com.yizhibo.video.bean.pay.OptionListEntity;
public class ExchangeCoinsAdapter extends BaseAdapter {
    private Context context;
    private List<OptionListEntity> mList;
    private Map<Integer, Boolean> isCheckMap = new HashMap<Integer, Boolean>();
    private int lastPosition;
    private int checkedRmb;
    public ExchangeCoinsAdapter(Context context) {
        this.context = context;
        mList = new ArrayList<OptionListEntity>();
    }
    public void setData(List<OptionListEntity> list) {
        mList = list;
    }
    @Override
    public int getCount() {
        return mList.size();
    }
    @Override
    public Object getItem(int i) {
        return null;
    }
    @Override
    public long getItemId(int i) {
        return i;
    }
    @Override
    public View getView(final int i, View view, ViewGroup viewGroup) {
        ViewHolder viewHolder = null;
        if (view == null) {
            view = LayoutInflater.from(context).inflate(R.layout.item_exchange_coins, viewGroup, false);
            viewHolder = new ViewHolder();
            viewHolder.exchangeCoinsTv = (TextView) view.findViewById(R.id.exchange_coins_tv);
            viewHolder.exchangeGiveCoinsTv = (TextView) view.findViewById(R.id.exchange_coins_give_tv);
            viewHolder.exchangeMoneyCb = (CheckBox) view.findViewById(R.id.exchange_money_tv);
            view.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) view.getTag();
        }
        final OptionListEntity model = mList.get(i);
        viewHolder.exchangeCoinsTv.setText(context.getString(R.string.e_coin_count_rear, model.getEcoin()));
        viewHolder.exchangeGiveCoinsTv
                .setText(context.getString(R.string.e_coin_give_count_rear, model.getFree()));
        viewHolder.exchangeMoneyCb
                .setText(context.getString(R.string.cash_count_simple, model.getRmb() / 100));
        viewHolder.exchangeMoneyCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                if (isCheckMap.size() > 0) {
                    isCheckMap.remove(lastPosition);
                }
                checkedRmb = model.getRmb();
                isCheckMap.put(i, true);
                lastPosition = i;
                ExchangeCoinsAdapter.this.notifyDataSetChanged();
            }
        });
        if (isCheckMap != null && isCheckMap.containsKey(i)) {
            viewHolder.exchangeMoneyCb.setSelected(isCheckMap.get(i));
        } else {
            viewHolder.exchangeMoneyCb.setSelected(false);
        }
        return view;
    }
    public int getCheckedRmb() {
        return checkedRmb;
    }
    protected static class ViewHolder {
        TextView exchangeCoinsTv;
        TextView exchangeGiveCoinsTv;
        CheckBox exchangeMoneyCb;
    }
}