Hinzufügen eines Bildes zu einem panel mit Java AWT

Bitte, bitte, bitte -nicht - verwenden Sie das JLabel. Während das-ist - der einfachste Weg, es ist auch eine schlechte Gewohnheit und führt zu Problemen, wenn Sie Bilder haben, die nicht der tatsächlichen Größe Sie angezeigt werden sollen.

Die zweite Antwort ist auf dem richtigen Weg, aber hat immer noch das gleiche problem.

Hier ist eine Klasse, die ich geschrieben habe in der Vergangenheit das ist, was Sie brauchen:

Wird es auch Ihnen erlauben, um die spezifische Größe, wenn Sie wollen; es wird das Bild zu skalieren, am besten die Platte, und richten Sie das Bild als gut.

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Insets;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.io.File;

import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.SwingConstants;

public class ImagePanel extends JComponent implements SwingConstants, Printable {

    private Image image;
    private int verticalAlignment = CENTER;
    private int horizontalAlignment = CENTER;

    public ImagePanel() {}

    public ImagePanel(Image image) {
        setImage(image);
    }

    public Image getImage() {
        return image;
    }

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

    public void setImage(String file) {
        setImage(new ImageIcon(file).getImage());
    }

    public void setImage(File file) {
        setImage(new ImageIcon(file.getAbsolutePath()).getImage());
    }

    public void setImage(byte[] imageData) {
        setImage(imageData==null ? null : new ImageIcon(imageData).getImage());
    }

    public int getVerticalAlignment() {
        return verticalAlignment;
    }

    /**
     * @beaninfo
     *        bound: true
     *         enum: TOP    SwingConstants.TOP
     *               CENTER SwingConstants.CENTER
     *               BOTTOM SwingConstants.BOTTOM
     *    attribute: visualUpdate true
     *  description: The alignment of the image along the Y axis.  
     */
    public void setVerticalAlignment(int verticalAlignment) {
        if( (verticalAlignment==TOP) || (verticalAlignment==CENTER) || (verticalAlignment==BOTTOM) )
            this.verticalAlignment = verticalAlignment;
        else
            throw new IllegalArgumentException("Invalid Vertical Alignment: " + verticalAlignment);
    }

    public int getHorizontalAlignment() {
        return horizontalAlignment;
    }

    /**
     * @beaninfo
     *        bound: true
     *         enum: LEFT    SwingConstants.LEFT
     *               CENTER SwingConstants.CENTER
     *               RIGHT SwingConstants.RIGHT
     *    attribute: visualUpdate true
     *  description: The alignment of the image along the X axis.  
     */
    public void setHorizontalAlignment(int horizontalAlignment) {
        if( (horizontalAlignment==LEFT) || (horizontalAlignment==CENTER) || (horizontalAlignment==RIGHT) )
            this.horizontalAlignment = horizontalAlignment;
        else
            throw new IllegalArgumentException("Invalid Horizontal Alignment: " + horizontalAlignment);
    }

    @Override
    public Dimension getPreferredSize() {
        if(image == null)
            return super.getPreferredSize();
        else
            return new Dimension(image.getWidth(this), image.getHeight(this));
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);

        if(image==null)
            return;

        Insets insets = getInsets();
        int x = insets.left;
        int y = insets.top;

        int w = getWidth() - insets.left - insets.right;
        int h = getHeight() - insets.top - insets.bottom;

        int src_w = image.getWidth(null);
        int src_h = image.getHeight(null);

        double scale_x = ((double)w)/src_w;
        double scale_y = ((double)h)/src_h;

        double scale = Math.min(scale_x, scale_y);

        int dst_w = (int)(scale * src_w);
        int dst_h = (int)(scale * src_h);

        int dx = x + (w-dst_w)/2;
        if(horizontalAlignment==LEFT)
            dx = x;
        else if(horizontalAlignment==RIGHT)
            dx = x + w - dst_w; 

        int dy = y + (h-dst_h)/2;
        if(verticalAlignment==TOP)
            dy = y;
        else if(verticalAlignment==BOTTOM)
            dy = y + h - dst_h; 

        g.drawImage(image, dx, dy, dx+dst_w, dy+dst_h, 0, 0, src_w, src_h, null);
    }

    public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {

        if(pageIndex>0 || image==null)
            return NO_SUCH_PAGE;

        double w = pageFormat.getImageableWidth();
        double h = pageFormat.getImageableHeight();

        int src_w = image.getWidth(null);
        int src_h = image.getHeight(null);

        double scale_x = w/src_w;
        double scale_y = h/src_h;

        double scale = Math.min(scale_x, scale_y);

        int dst_w = (int)(scale * src_w);
        int dst_h = (int)(scale * src_h);

        int dx = (int)((w-dst_w)/2);

        int dy = (int)((h-dst_h)/2);

        graphics.drawImage(image, dx, dy, dx+dst_w, dy+dst_h, 0, 0, src_w, src_h, null);

        return PAGE_EXISTS;
    }
}

InformationsquelleAutor Reverend Gonzo