jscrollpanedemo.java

这是《Java案例精粹150例（上册）》一书配套的源代码。

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

public class JScrollPaneDemo implements ActionListener {
	private JScrollPane scrollPane;

	public JScrollPaneDemo() {
		JFrame f = new JFrame("JScrollPaneDemo");
		Container contentPane = f.getContentPane();
		JLabel label1 = new JLabel(new ImageIcon(".\\icons\\Hill.jpg"));
		JPanel panel1 = new JPanel();
		panel1.add(label1);
		scrollPane = new JScrollPane();
		//设置窗口显示的内容窗格为panel1
		scrollPane.setViewportView(panel1);
		//设置水平与垂直表头
		scrollPane.setColumnHeaderView(new JLabel("水平表头"));
		scrollPane.setRowHeaderView(new JLabel("垂直表头"));
		//设置scrollPane的边框凹陷立体边框。
		scrollPane.setViewportBorder(BorderFactory
				.createBevelBorder(BevelBorder.LOWERED));
		//设置scrollPane的边角图案
		scrollPane.setCorner(JScrollPane.UPPER_LEFT_CORNER, new JLabel(
				new ImageIcon(".\\icons\\Sunset.jpg")));
		scrollPane.setCorner(JScrollPane.UPPER_RIGHT_CORNER, new JLabel(
				new ImageIcon(".\\icons\\Sunset.jpg")));
		JPanel panel2 = new JPanel(new GridLayout(3, 1));
		JButton b = new JButton("显示水平滚动轴");
		b.addActionListener(this);
		panel2.add(b);
		b = new JButton("不要显示水平滚动轴");
		b.addActionListener(this);
		panel2.add(b);
		b = new JButton("适时显示水平滚动轴");
		b.addActionListener(this);
		panel2.add(b);
		contentPane.add(panel2, BorderLayout.WEST);
		contentPane.add(scrollPane, BorderLayout.CENTER);
		f.setSize(new Dimension(350, 220));
		f.show();
		f.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
	}

	public void actionPerformed(ActionEvent e) {
		if (e.getActionCommand().equals("显示水平滚动轴")) {
			scrollPane.setHorizontalScrollBarPolicy
			    (JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
		}
		if (e.getActionCommand().equals("不要显示水平滚动轴")) {
			scrollPane.setHorizontalScrollBarPolicy
			    (JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
		}
		if (e.getActionCommand().equals("适时显示水平滚动轴")) {
			scrollPane.setHorizontalScrollBarPolicy
			    (JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
		}
		scrollPane.revalidate();//重新显示JScrollPane形状。
	}

	public static void main(String[] args) {
		new JScrollPaneDemo();
	}
}