import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class text extends JFrame implements ActionListener
{
int red,green,blue;
JPanel p =new JPanel();
JButton b = new JButton("按键");
public text()
{
this.add(p);
p.add(b);
b.addActionListener(this);
this.setVisible(true);
this.setSize(300,200);
this.setDefaultCloseOperation(this.EXIT_ON_CLOSE);
}
public void actionperformed(ActionEvent e)
{
red = (int)(Math.random()*256);
green = (int)(Math.random()*256);
blue = (int)(Math.random()*256);
p.setBackground(new Color(red,green,blue));
this.setTitle("红："+ red+" 绿："+green +" 蓝："+blue);
}
public static void main(String[] args)
{
new text();
}
}

刚忘了,告诉public class text extends JFrame implements ActionListener不是抽象类,而且未覆盖
我不知道要怎么改,谢谢大家了

我都实现了啊
还有就是抽象类,我定义了

哈哈
谢谢了
是大写的事情
我真该打我自己了,那么简单的问题
谢谢了

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class aa extends JFrame implements KeyListener
{
JPanel p = new JPanel();
JTextField tf = new JTextField(20);
aa()
{
this.add(p);
tf.addKeyListener(this);
p.add(tf);
this.setVisible(true);
this.setSize(300,200);
this.setLocation(200,200);
this.setDefaultCloseOperation(this.EXIT_ON_CLOSE);
}
public void KeyTyped(KeyEvent e)
{
if(e.getKeyChar()=='a')
tf.setBackground(Color.yellow);
}
public void KeyPressed(KeyEvent e)
{
tf.setBackground(Color.red);
}
public void KeyReleased(KeyEvent e)
{
tf.setBackground(Color.black);
}
public static void main(String[] args)
{
new aa();
}
}
这个是那错了那?
我真的找不到了

晕了,这个也是大小写的问题