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Javaで画像を印刷する必要があります。そこで、インターフェースprint()のメソッドを実装しました。Printableただし、プリンターは常に元の画像の一部のみを印刷します。画像を印刷領域 (A4) に合わせて、プリンターが画像の一部ではなく画像全体を印刷できるようにするにはどうすればよいですか? 今私のコードは次のようになります：

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


    if (pageIndex >= images.size()) {
        return Printable.NO_SUCH_PAGE;
    }
    RenderedImage image;


    Graphics2D graphics2D = (Graphics2D) graphics;

    image = new NullOpImage((RenderedImage) images.get(pageIndex), null, null, OpImage.OP_IO_BOUND);


    double x = (pageFormat.getImageableWidth() - image.getWidth())/2 + pageFormat.getImageableX();
    double y = (pageFormat.getImageableHeight() - image.getHeight())/2 + pageFormat.getImageableY();


    graphics2D.drawRenderedImage(image, AffineTransform.getTranslateInstance(x, y));

    return PAGE_EXISTS;
}
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使用可能な領域に合わせて画像を縮小する必要があります。

private int currentPage = -1;
private Image cachedScaledImage = null;

public double getScaleFactor(int iMasterSize, int iTargetSize) {
    double dScale = 1;
    if (iMasterSize > iTargetSize) {
        dScale = (double) iTargetSize / (double) iMasterSize;
    } else {
        dScale = (double) iTargetSize / (double) iMasterSize;
    }
    return dScale;
}

public double getScaleFactorToFit(BufferedImage img, Dimension size) {
    double dScale = 1;
    if (img != null) {
        int imageWidth = img.getWidth();
        int imageHeight = img.getHeight();
        dScale = getScaleFactorToFit(new Dimension(imageWidth, imageHeight), size);
    }
    return dScale;
}

public double getScaleFactorToFit(Dimension original, Dimension toFit) {
    double dScale = 1d;
    if (original != null && toFit != null) {
        double dScaleWidth = getScaleFactor(original.width, toFit.width);
        double dScaleHeight = getScaleFactor(original.height, toFit.height);

        dScale = Math.min(dScaleHeight, dScaleWidth);
    }
    return dScale;
}

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

    if (pageIndex >= images.size()) {
        return Printable.NO_SUCH_PAGE;
    }
    RenderedImage image;


    Graphics2D graphics2D = (Graphics2D) graphics;

    int width = (int)Math.round(pageFormat.getImageableWidth());
    int height = (int)Math.round(pageFormat.getImageableHeight());

    if (currentPage != pageIndex || cachedScaledImage == null) {
        currentPage = pageIndx;    

        image = new NullOpImage((RenderedImage) images.get(pageIndex), null, null, OpImage.OP_IO_BOUND);

        BufferedImage imageCopy = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB);
        Graphics2D g2d = imageCopy.createGraphics();
        g2d.drawImage(imageCopy, 0, 0, null);
        g2d.dispose();

        double scaleFactor = getScaleFactorToFit(new Dimension(image.getWidth(), image.getHeight()), new Dimension(width, height));

        int imageWidth = (int)Math.round(image.getWidth() * scaleFactor);
        int imageHeight = (int)Math.round(image.getHeight() * scaleFactor);

        double x = ((pageFormat.getImageableWidth() - imageWidth) / 2) + pageFormat.getImageableX();
        double y = ((pageFormat.getImageableHeight() - imageHeight) / 2) + pageFormat.getImageableY();

        cachedScaledImage = imageCopy.getScaledInstance(imageWidth, imageHeight, Image.SCALE_SMOOTH);

    }

    graphics2D.drawRenderedImage(cachedScaledImage, AffineTransform.getTranslateInstance(x, y));

    return PAGE_EXISTS;
}
于 2012-08-29T09:07:19.087 に答える