Android listView 中响应Button点击事件

class WqrAdapter extends SimpleAdapter {

LayoutInflater inflater;

@Override
public View getView(int position, View convertView, ViewGroup parent) {

final Holder holder;
final int num=position;
if(convertView!=null){
holder=(Holder) convertView.getTag();
}else {
holder=new Holder();
convertView=inflater.inflate(R.layout.wqr_list_row, null);
holder.xqButton=(Button) convertView.findViewById(R.id.ButtonGn);
convertView.setTag(holder);
}

OnClickListener listener=new OnClickListener(){
@Override
public void onClick(View v)
{
//	                if(v==holder.xqButton){
//	                    Toast.makeText(context, "pause", Toast.LENGTH_SHORT).show();
System.out.println(num);
//	                }

}
};

holder.xqButton.setOnClickListener(listener);

return super.getView(position, convertView, parent);
}

public WqrAdapter(Context context, List<? extends Map<String, ?>> data,
int resource, String[] from, int[] to) {
super(context, data, resource, from, to);
//			this.context=context;
inflater=LayoutInflater.from(context);
// TODO Auto-generated constructor stub
}
}

class Holder{
public Button xqButton;
}