按照你的要求编写的Java小程序如下:
//改变JLabel背景颜色的小程序
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
public class ChangeColor extends JApplet implements ActionListener{
JLabel jl=new JLabel();
JButton jb=new JButton("改变颜色");
public void init(){
jb.addActionListener(this);
jl.setOpaque(true);
add(jl,BorderLayout.CENTER);
add(jb,BorderLayout.SOUTH);
setSize(300, 300);
}
@Override
public void actionPerformed(ActionEvent ae) {
if(ae.getSource()==jb){
int red=(int)(Math.random()*256);
int green=(int)(Math.random()*256);
int blue=(int)(Math.random()*256);
jl.setBackground(new Color(red,green,blue));
}
}
}
运行结果:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/b90e7bec54e736d1828374e09c504fc2d4626942?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)