引用MouseListener要用abstract来修饰吗????
这是在书上看到的一个原程序。
public class Second extends Frame implements ActionListener,MouseListener{
TextArea msg=new TextArea();
PopupMenu pm=new PopupMenu();
MenuItem i1=new MenuItem("复制");
MenuItem i2=new MenuItem("剪切");
MenuItem i3=new MenuItem("粘贴");
Second(){
setTitle("弹出菜单");
setSize(350,200);
addWindowListener(new WindowAdapter(){
public void WindowClosing(WindowEvent e){
System.exit(0);
}
});
add(msg);
msg.add(pm);
pm.add(i1);
pm.add(i2);
pm.add(i3);
i1.addActionListener(this);
i2.addActionListener(this);
i3.addActionListener(this);
msg.addMouseListener(this);
show();
}
public void actionPerformed(ActionEvent e){
msg.append("你选择了"+e.getActionCommand()+"\n");
}
public void mouseReleased(MouseEvent e){
if (e.isPopupTrigger())
pm.show(this,e.getX(),e.getY());
}
public void mouseClicked(MouseEvent e){}
public void mouseEnter(MouseEvent e){}
public void mouseExited(MouseEvent e){}
public void mousePressed(MouseEvent e){}
public static void main(String args[]){
new Second();
//System.out.println("你好莱坞");
}
}
说什么没有加abstract来修饰我倒呀。。。。