sliderexample.java

中国水利水电出版社java程序设计教程,附源码

//SliderExample.java

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

public class SliderExample
{  
	public static void main(String[] args)
	{  
		SliderFrame frame = new SliderFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.show();
	}
}

class SliderFrame extends JFrame
{
	public SliderFrame()
	{
		setTitle("SliderExample");
		setSize(WIDTH, HEIGHT);

		Container contentPane = getContentPane();
		
		AgeListener myAgeListener = new AgeListener();
		//建立容纳滑块的面板
		agePanel = new JPanel();

		//新建缺省样式的滑块
		JSlider ageSlider = new JSlider();
		ageSlider.addChangeListener(myAgeListener);
		agePanel.add(choiceLabel);
		agePanel.add(ageSlider);
		
		//新建竖向滑块，并指定最大值和初始值。	
		ageSlider = new JSlider(SwingConstants.VERTICAL, 0, 120, 20);
		ageSlider.addChangeListener(myAgeListener);
		agePanel.add(ageSlider);

		//建立容纳文本域的面板
		JPanel textPanel = new JPanel();
		//新建文本域
		myTextField = new JTextField("", 15);
		textPanel.add(choosedLabel, BorderLayout.NORTH);
		textPanel.add(myTextField, BorderLayout.CENTER);

		contentPane.add(agePanel, BorderLayout.NORTH);
		contentPane.add(textPanel, BorderLayout.CENTER);
	}

	//两个滑块共用的事件监听器
	private class AgeListener
		implements ChangeListener
	{
		public void stateChanged(ChangeEvent event)
		{
			JSlider sourceSlider = (JSlider)event.getSource();
			myTextField.setText("" + sourceSlider.getValue());
		}
	}

	public static final int WIDTH = 400;
	public static final int HEIGHT = 280;
	public static final JLabel choosedLabel = new JLabel("Choosed age:");
	public static final JLabel choiceLabel = new JLabel("Please choose age:");

	private JTextField myTextField;
	private JPanel agePanel;
}