rgbdemo.java

来自「java课件 java课件 java课件 java课件」· Java 代码 · 共 52 行

// RGBDemo.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class RGBDemo extends JFrame{
  JButton btn1,btn2,btn3;
  JPanel jp1,jp2;
  
  public RGBDemo(){
      super("Red Green Blue Demo");
  	  
      btn1 = new JButton("Red");
      btn2 = new JButton("Green");
      btn3 = new JButton("Blue");
      jp1 = new JPanel();
      jp2 = new JPanel();
      jp2.add(btn1);
      jp2.add(btn2);
      jp2.add(btn3);
      jp2.setBackground(Color.CYAN);    
      Container cp = getContentPane();
      cp.add(jp1,BorderLayout.CENTER);
      cp.add(jp2,BorderLayout.SOUTH);
      
      
      AL listener = new AL();
      btn1.addActionListener(listener);
      btn2.addActionListener(listener);
      btn3.addActionListener(listener);
  }
  class AL implements ActionListener{
    public void actionPerformed(ActionEvent e){
     Color c = null; 
     if((JButton)e.getSource()==btn1)
       c = Color.RED;
     else if((JButton)e.getSource()==btn2)
       c = Color.GREEN;
     else if((JButton)e.getSource()==btn3)
       c = Color.BLUE;
     jp1.setBackground(c);  
    }
  }
  
  public static void main(String[]args){
    RGBDemo frame = new RGBDemo();
    frame.setSize(300,200);
    frame.setLocation(400,300);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
}