【正确答案】参考代码如下：
import java.awt.*;
import java.awt.event.* ;
public class ButtonDemo implements ActionListener{
private Button ok,cancel;
public ButtonDemo(){
Frame f = new Frame("测试按钮");
f.setLayout(new FlowLayout());
ok = new Button("OK");
ok.addActionListener(this);
cancel= new Button("Cancel");
cancel.addActionListener(this);
f.add(ok);
f.add(cancel);
f.setSize(200,100);
f.setVisible(true) ;
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==ok){
System.out.println("您按了OK按钮！");
}
else{
System.out.println("您按了Cancel按钮！");
}
}
public static void main(String args[ ]){
new ButtonDemo();
}
}
如果用Swing组件实现，则参考代码如下：
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.* ;
public class JButtonDemo implements ActionListener{
private JButton ok,cancel;
private JTextField tf;
public JButtonDemo(){
JFrame f = new JFrame("测试按钮");
f.setLayout(new FlowLayout());
Container c=f.getContentPane();
tf=new JTextField(20);
ok = new JButton("OK");
cancel= new JButton("Cancel");
ok.addActionListener(this);
cancel.addActionListener(this);
c.add(tf);
c.add(ok);
c.add(cancel);
f.setSize(200,100);
f.setVisible(true) ;
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==ok){
tf.setText("您按了OK按钮！");
}
else{
tf.setText("您按了Cancel按钮！");
}
}
public static void main(String args[ ]){
new JButtonDemo();
}
}
【答案解析】