Java Swing的背景圖片按比例縮放

Java Swing的背景圖片按比例縮放

1. import java.awt.*;
2. import java.awt.image.BufferedImage;
3. import javax.swing.Icon;
4. import javax.swing.ImageIcon;
5. import javax.swing.JFrame;
6. import javax.swing.JLabel;
8. public class ScaleIcon implements Icon {
10. private BufferedImage i = null;
11. private Icon icon = null;
13. public ScaleIcon(Icon icon) {
14. this.icon = icon;
15. }
17. @Override
18. public int getIconHeight() {
19. return icon.getIconHeight();
20. }
22. @Override
23. public int getIconWidth() {
24. return icon.getIconWidth();
25. }
27. public void paintIcon(Component c, Graphics g, int x, int y) {
28. float wid = c.getWidth();
29. float hei = c.getHeight();
30. int iconWid = icon.getIconWidth();
31. int iconHei = icon.getIconHeight();
33. Graphics2D g2d = (Graphics2D) g;
34. g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
35. g2d.scale(wid / iconWid, hei / iconHei);
36. icon.paintIcon(c, g2d, 0, 0);
37. }
39. public static void main(String[] args) {
40. ScaleIcon icon = new ScaleIcon(new ImageIcon(ClassLoader.getSystemResource("img/main.jpg")));
41. JLabel label = new JLabel(icon);
42. JFrame frame = new JFrame();
43. frame.getContentPane().add(label, BorderLayout.CENTER);
44. // frame.getContentPane().add(new JButton("click"),BorderLayout.NORTH);
45. frame.setSize(800, 600);
46. frame.setLocationRelativeTo(null);
47. frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
48. frame.setVisible(true);
49. }
50. }