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无法在OSX上的Swing中显示图像

swing java

Ceilingfish · 技术社区 · 15 年前

我觉得我有点傻了,因为我已经有一段时间没有做Swing编程了,但是我试图在屏幕上画一个简单的图像,我没有得到我所期望的

public class ImageApp {

    public static void main(String[] args) throws MalformedURLException, IOException {
        final Image image = ImageIO.read(new File("/Library/WebServer/Documents/image.gif"));

        final JPanel component = new JPanel(){

            public void paint(final Graphics g) {
                System.out.println("Drawing image "+image.getWidth(null)+" "+image.getHeight(null));
                g.drawString("hello", 0,0);
                g.drawImage(image,this.getWidth()/2,this.getHeight()/2, 100, 100, Color.blue,this);
                super.paint(g);
            }
        };

        final JFrame frame = new JFrame();

        frame.add(component);
        frame.setSize(100, 100);

        frame.pack();
        frame.setVisible(true);
    }

}

这将呈现一个空白窗口,其大小似乎不到100100。是否有一些其他的步骤,我需要执行的图形显示在屏幕上,或大小得到尊重?

我在osx10.6上使用JDK6

2 回复 | 直到 15 年前

Community Mohan Dere 8 年前

在Swing中,您应该覆盖 paintComponent() ,不是 paint() .

附录:例如,见下文。在一篇评论中,@eugener提出了一个关于使用 JLabel 作为替代方案 image container .

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Image;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class ImageApp {

    public static void main(String[] args) throws IOException {
        final Image image = ImageIO.read(new File("image.jpg"));
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                final JPanel component = new JPanel() {

                    @Override
                    public void paintComponent(final Graphics g) {
                        g.drawImage(image, 0, 0, null);
                    }

                    @Override
                    public Dimension getPreferredSize() {
                        return new Dimension(
                            image.getWidth(this), image.getHeight(this));
                    }
                };

                final JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(component);
                frame.pack();
                frame.setVisible(true);
            }
        });
    }
}

Rekin 15 年前

试试这个:

public class ImageApp {

    public static void main(String[] args) throws MalformedURLException, IOException {
        final Image image = ImageIO.read(new File("/Library/WebServer/Documents/image.gif"));

        final JPanel component = new JPanel() {

            @Override
            public void paintComponent(final Graphics g) {
                super.paintComponent(g);
                System.out.println("Drawing image " + image.getWidth(null) + " " + image.getHeight(null));
                g.drawString("hello", 0,10);
                g.drawImage(image, this.getWidth() / 2, this.getHeight() / 2, 100, 100, Color.blue, this);
            }
        };

        final JFrame frame = new JFrame();

        frame.add(component);
        frame.setSize(100, 100);

        frame.setVisible(true);
    }
}