public class CalculatorEvent extends CalculatorGUI{
ButtonEvent bEObj;
public CalculatorEvent(){
bEObj=new ButtonEvent();
button0.addActionListener(bEObj); 
        }
class ButtonEvent implements ActionListener{
public void actionPerformed(ActionEvent e){
Object obj=e.getSource();

if(obj==button0){
                             textanswer.setText("hello");
}
                 }
        }
}
但在键盘上按下数字0键时,能实现textanswer.setText("hello");在这里怎样调用键盘事件?谢谢指教