如何从PNG图片构建个人JFrame

Question

我尝试从PNG图片构建我的个人JFrame.但Mac OSX 10.8和Windows 7之间存在不同的行为.(我必须使用JDK 6)

这是我的代码:

[...]

public Fenetre()
{

    this.setLocationRelativeTo(null);
    this.setUndecorated(true);
    this.setBackground(new Color(0,0,0,0));

    try {
        image = ImageIO.read(this.getClass().getResource("/Images/frame.png"));     
    } catch (IOException e) {
        e.printStackTrace();
    }

    this.setSize(image.getWidth(),image.getHeight());                
    this.setLayout(null);


    panel = new JPanel();
    JButton quit = new JButton("Quitter");
    panel.add(quit);
    Dimension size = panel.getPreferredSize();
    panel.setBounds(67, 45, size.width, size.height);

    this.add(panel);

    this.addMouseListener(this);
    this.addMouseMotionListener(this);
    this.setVisible(true);      

}

public void paint(Graphics g) {

    Graphics2D g2 =(Graphics2D) g;
    g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC)); // SRC_ATOP > Windows
    g2.drawImage(image, 0, 0, this);
    panel.update(panel.getGraphics());

}

[...]

Mac OSX 10.8(AlphaComposite = SRC)上的结果:

http://imageshack.us/photo/my-images/15/maczr.png/

然后,在Windows 7(AlphaComposite = SRC_ATOP)上,在启动时和移动它时,我可以看到:

http://imageshack.us/photo/my-images/16/windowsqu.jpg/

怎么样？

Answer 1

你的代码不完整,但在我看来,你正在重写JFrame的paint()方法.你永远不应该这样做(除非你知道你在做什么,你调用super.paint(..))!

如果要在框架中显示图像,则:

a)将带有图像的JLabel添加到框架
b)或通过覆盖paintComponent()方法在JPanel上进行自定义绘制,然后将面板添加到框架中.