新手程序员在这里:
我刚做了我的第一个按钮。我希望按钮更改标签“Hello World!” 到“你好宇宙!”。我尝试寻找通过 更改标签的方法public void actionPerformed(ActionEvent e)
,但没有找到任何方法。如果有人愿意向我解释如何更改评论部分public void actionPerformed(ActionEvent e)
以更改标签,请解释!
谢谢!
我的代码:
package game;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Javagame extends JPanel implements ActionListener{
double x=Math.random()*500;
double y=Math.random()*500;
protected JButton b1;
public Javagame() {
b1 = new JButton("Button!");
b1.setActionCommand("change");
b1.addActionListener(this);
add(b1);
}
public void actionPerformed(ActionEvent e) {
if ("change".equals(e.getActionCommand())) {
//I want a code here that changes "Hello World" to "Hello Universe". Thank you.
}
}
private static void createWindow(){
JFrame frame = new JFrame("Javagame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setPreferredSize(new Dimension(500,500));
JLabel label = new JLabel("Hello World!", SwingConstants.CENTER);
label.setFont(new Font("Arial", Font.BOLD, 20));
label.setForeground(new Color(0x009900));
Javagame newContentPane = new Javagame();
newContentPane.setOpaque(true);
frame.setContentPane(newContentPane);
frame.getContentPane().add(label, BorderLayout.CENTER);
frame.setLocationRelativeTo(null);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
createWindow();
}
}