java - JInternalFrame 图像显示；

Question

我尝试向 JInternalFrame 添加图像。我的paint()看起来像这样:

    public void paint (Graphics g) {
        //this should draw the loaded image
        if (bufferedImage != null) {
            g.drawImage(bufferedImage, getSize().width/2 - bufferedImage.getWidth()/2,
            getInsets().top+20, this);
        }
    }   

图像确实加载并显示，但窗口标题栏(应该有名称、最小值、最大值和关闭的标题栏)消失了。当我将鼠标移动到应有的位置时，最小/最大/关闭按钮会重新出现，当我将鼠标移动到标题栏上时，我可以拖动 整个窗口。

我应该使用其他方法来代替 Paint() 方法吗？

谢谢

Answer 1

除非您有充分的理由直接绘制到 JInternalFrame 中，否则为什么不创建一个 new JLabel(new ImageIcon(bufferedimage)) 并将其 add() 到 JInternalFrame 中？

一个例子:

import java.awt.BorderLayout;
import java.awt.Image;
import java.io.IOException;
import java.net.URL;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;

public class PictureDesktop extends JDesktopPane {

    public static void main(final String[] args) throws IOException {
        // some Wikipedia Commons Pictures of the Day
        final URL url1 = new URL("http://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Hacienda_jaral_de_berrios.jpg/300px-Hacienda_jaral_de_berrios.jpg");
        final URL url2 = new URL("http://upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Magellanic_penguin%2C_Valdes_Peninsula%2C_e.jpg/300px-Magellanic_penguin%2C_Valdes_Peninsula%2C_e.jpg");
        final URL url3 = new URL("http://upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Marmolada_Sunset.jpg/300px-Marmolada_Sunset.jpg");

        final PictureDesktop desktop = new PictureDesktop();
        desktop.addPicture(ImageIO.read(url1));
        desktop.addPicture(ImageIO.read(url2));
        desktop.addPicture(ImageIO.read(url3));

        final JFrame frame = new JFrame("Pictures");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(BorderLayout.CENTER, desktop);
        frame.setSize(720, 480);
        frame.setVisible(true);
    }

    public void addPicture(final Image image) {
        add(createFrame(image));
    }

    private static int frames;

    private JInternalFrame createFrame(final Image image) {
        frames++;

        final JInternalFrame frame = new JInternalFrame("Picture " + frames);
        frame.add(BorderLayout.CENTER, new JLabel(new ImageIcon(image)));
        // without pack and setVisible, the frame isn't shown
        frame.pack();
        frame.setVisible(true);

        // cascade frames 
        frame.setLocation(40 * frames, 40 * frames);

        return frame;
    }
}