本题中，主窗口有一个按钮“打开对话框”和一个文本域，单击按钮“打开对话框”后会弹出一个对话框，对话框上有两个按钮“Yes”和“No”，单击对话框上的“Yes”和“No”按钮后返回主窗口，并在右侧文本域中显示刚才所单击的按钮信息。
import java. awt. event. * ;
import java. awt. * ;
class MyDialog______implements ActionListener
static final int YES=1, NO=0;
int message=-1; Button yes, no;
MyDialog(Frame f, String s, boolean b)
super(f, s, b);
yes=new Button("Yes"); yes. addActionListener(this);
no=new Button ("No"); no. addActionListener(this);
setLayout (new FlowLayout());
add(yes); add(no);
setBounds(60,60,100,100);
addWindowListener(new WindowAdapter()
public void windowClosing(WindowEvent e)
message=-1; setVisible(false);
);
public void actionPerformed(ActionEvent e)
if(e. getSource()=yes)
message=YES;
setVisible(false);
else if(e. getSource()==no)
message=NO;
setVisible(false);
public int getMessage()
return message;
class Dwindow extends Frame implements ActionListenet
TextArea text; Button button; MyDialog dialog;
Dwindow(String s)
super(s);
text=new TextArea(5,22); button=new Button("打开对话框");
button. addActionListener(this);
setLayout(new FlowLayout());
add(button); add(text);
dialog=new MyDialog(this, "Dialog", true);
setBounds(60,60,300,300); setVisible(true);
validate();
addWindowListener(new WindowAdapter()
public void windowClosing(WindowEvent e)
System. exit(0);
);
public void actionPerformed(ActionEvent e)
if(e. getSource()==button)
______;
if(dialog, getMessage()==MyDialog. YES)
text. append("\n你单机了对话框的yes按钮");
else if(dialog. getMessage()==MyDialog. NO)
text. append("\n你单机了对话框的No按钮");
public class java2
public static void main(String args[])
new Dwindow("java2");
