Question

我想调整图片大小，但显示它总是出错。

我该怎么办？

public class Panel extends JPanel {

    private ImageIcon imgIcon; 

    public Panel(){
        super();
        File imageFile=new File("mar.jpg"); 
        try {
            BufferedImage bi = ImageIO.read(imageFile);
            ImageIcon imgIcon = new ImageIcon(bi);
            imgIcon = new ImageIcon(bi.getScaledInstance(400,400, Image.SCALE_DEFAULT));        
        } catch (IOException e) {
            System.err.println("error");
            e.printStackTrace();
        }

        Dimension dimension=new Dimension(1400,1000);
        setPreferredSize(dimension);
    }
    @Override
    public void paintComponent(Graphics g){
        Graphics2D g2d=(Graphics2D)g;
        g2d.drawImage(imgIcon.getImage(),0,0,this);
    }
}

Answer 1

这就是我过去的做法：

public class ImagePanel extends JPanel{

    private BufferedImage image;

    public PanelImage(){}


    public void setImage(BufferedImage image){
        this.image = image;
    }

    private Image scaleImage(){
        if(image==null)return null;
        int width = getWidth();
        int height = (int)((getWidth()/(double)image.getWidth())*image.getHeight());
        return image.getScaledInstance(width, height, Image.SCALE_SMOOTH);
    }

    @Override protected void paintComponent(Graphics g){
        super.paintComponent(g);
        Image scaledImage = scaleImage();
        if(scaledImage != null){
            int x = 0;
            int y = (int)((getHeight()/2d)-(scaledImage.getHeight(null)/2d));
            g.drawImage(scaledImage, x, y, null);
        }
    }
}

此外，请不要将您的课程命名为Panel，因为已经存在awt.Panel并且会导致歧义问题。

显示调整大小的图片

1 个答案: