如何以指定角度(例如25度)旋转页面?
PdfCanvas content = new PdfCanvas(pdfDoc.addNewPage());
for (int i =1 ; i <= srcDoc.getNumberOfPages(); i++) {
PdfFormXObject page = srcDoc.getPage(i).copyAsFormXObject(pdfDoc);
content.add(page...);
}
我可以设置RotationAngle与PdfFormXObject一起使用吗?还是有其他方法?
最简单的方法是使用AffineTransform
(来自com.itextpdf.kernel.geom
):
PdfCanvas content = new PdfCanvas(pdfDoc.addNewPage());
PageSize pageSize = pdfDoc.getDefaultPageSize();
PdfFormXObject page = srcDoc.getPage(1).copyAsFormXObject(pdfDoc);
AffineTransform transform = AffineTransform.getRotateInstance(25 * Math.PI / 180, (pageSize.getLeft() + pageSize.getRight())/2, (pageSize.getBottom() + pageSize.getTop())/2);
content.concatMatrix(transform);
content.addXObject(page, 0, 0);
([RotatePageXObject test testAddPage25Degree
)
AffineTransform.getRotateInstance
被记录为
* Get an affine transformation representing a counter-clockwise rotation over the passed angle,
* using the passed point as the center of rotation
因此,我们将角度(转换为弧度)和页面中心的坐标输入给它。
应用于此源PDF会创建此结果: