exercise13_4.java

一款用java编写的小型数据库管理系统

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.TitledBorder;
public class Exercise13_4 extends JFrame{
	private JPanel jp=new JPanel();
	private JLabel jlRed=new JLabel("Red");
	private JLabel jlGreen=new JLabel("Green");
	private JLabel jlBlue=new JLabel("Blue");
    private JScrollBar jsRed=new JScrollBar(JScrollBar.HORIZONTAL);
    private JScrollBar jsGreen=new JScrollBar(JScrollBar.HORIZONTAL);
    private JScrollBar jsBlue=new JScrollBar(JScrollBar.HORIZONTAL);
    protected MessagePanel messagePanel=new MessagePanel("");
    public Exercise13_4(){
		messagePanel.setBackground(new Color(0,0,0));
       	jp.setLayout(new GridLayout(3,2,5,5));
    	jp.setBorder(new TitledBorder("Choose colors"));
    	jp.add(jlRed);
    	jp.add(jsRed);
    	jp.add(jlGreen);
    	jp.add(jsGreen);
    	jp.add(jlBlue);
    	jp.add(jsBlue);

    	add(jp,BorderLayout.SOUTH);
    	add(messagePanel,BorderLayout.CENTER);
    	///红色滑块
    	jsRed.addAdjustmentListener(new AdjustmentListener(){
    		public void adjustmentValueChanged(AdjustmentEvent e) {
    			int value = jsRed.getValue();
    	        int maximumValue = 255;
    	        int minimumValue=0;
    	        Color c1=new Color(value,jsGreen.getValue()+5,jsBlue.getValue()+5);
    	        messagePanel.setBackground(c1);

    		}
    	});
    	///绿色滑块
    	jsGreen.addAdjustmentListener(new AdjustmentListener(){
    		public void adjustmentValueChanged(AdjustmentEvent e) {
    			int value = jsGreen.getValue();
    	        int maximumValue = 255;
    	        int minimumValue=0;
    	        Color c2=new Color(jsRed.getValue()+5,value,jsBlue.getValue()+5);
    	        messagePanel.setBackground(c2);

    		}
    	});
    	///蓝色滑块
    	jsBlue.addAdjustmentListener(new AdjustmentListener(){
    		public void adjustmentValueChanged(AdjustmentEvent e) {
    			int value = jsBlue.getValue();
    	        int maximumValue = 255;
    	        int minimumValue=0;
    	        Color c3=new Color(jsRed.getValue()+5,jsGreen.getValue()+5,value);
    	        messagePanel.setBackground(c3);

    		}
    	});

    }
    public static void main(String[] args) {
    	Exercise13_4 frame = new Exercise13_4();
        frame.setTitle("Exercise13_4");
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);

      }
}