代码:
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.util.Date;
import javax.swing.Timer;
import java.awt.event.ActionListener;
import javax.swing.*;
class TimePrinter implements ActionListener {
public void actionPerformed(ActionEvent event) {
Date now = new Date();
System.out.println("At the tone,the time is"+now);
Toolkit.getDefaultToolkit().beep();
}
}
class Test1 {
public static void main(String[] args) {
int delay = 1000; //milliseconds
ActionListener al = new TimePrinter();
Timer t = new Timer(delay,al);
t.start();
}
}
import java.awt.event.ActionEvent;
import java.util.Date;
import javax.swing.Timer;
import java.awt.event.ActionListener;
import javax.swing.*;
class TimePrinter implements ActionListener {
public void actionPerformed(ActionEvent event) {
Date now = new Date();
System.out.println("At the tone,the time is"+now);
Toolkit.getDefaultToolkit().beep();
}
}
class Test1 {
public static void main(String[] args) {
int delay = 1000; //milliseconds
ActionListener al = new TimePrinter();
Timer t = new Timer(delay,al);
t.start();
}
}
改代码编译无错执行,没有显示任何内容;
改为:


































不知道 为什么没有加那条代码就执行不出来????