C++实现添加图片水印到PDF文档

#include "Spire.Pdf.o.h"

using namespace Spire::Pdf;

int main()
{
	//创建PdfDocument的对象
	PdfDocument* document = new PdfDocument();

	//载入PDF文件
	document->LoadFromFile(L"C:/我们之间的距离.pdf");

	//载入图片
	PdfImage* img = PdfImage::FromFile(L"C:/Logo.png");

	//获取图片的高度和宽度
	int imageWidth = img->GetWidth();
	int imageHeight = img->GetHeight();

	for (int i = 0; i < document->GetPages()->GetCount(); i++)
	{
		//获取指定页面
		PdfPageBase* page = document->GetPages()->GetItem(i);

		//获取页面的高度和宽度
		float pageWidth = (float)(page->GetActualSize()->GetWidth());
		float pageHeight = (float)(page->GetActualSize()->GetHeight());

		//设置透明度
		page->GetCanvas()->SetTransparency(0.3f);

		//将图片绘制在页面中央
		page->GetCanvas()->DrawImage(img, pageWidth / 2 - imageWidth / 2, pageHeight / 2 - imageHeight / 2, imageWidth, imageHeight);
	}

	//保存文档
	document->SaveToFile(L"Output/单一图片水印.pdf");
	document->Close();
	delete document;
}

#include "Spire.Pdf.o.h"

using namespace Spire::Pdf;

void InsertTiledImageWatermark(PdfPageBase* page, PdfImage* img, int row, int column) {
    //创建平铺笔刷
    PdfTilingBrush* brush = new PdfTilingBrush(new SizeF(page->GetCanvas()->GetSize()->GetWidth() / (int)(row), page->GetCanvas()->GetSize()->GetHeight() / (int)(column)));
    //设置透明度
    brush->GetGraphics()->SetTransparency(0.3);
    //将图片绘制在笔刷上
    brush->GetGraphics()->DrawImage(img, new PointF((brush->GetSize()->GetWidth() - img->GetWidth()) / 2.f, (brush->GetSize()->GetHeight() - img->GetHeight()) / 2.f));
    //使用笔刷将图片绘制在页面上
    page->GetCanvas()->DrawRectangle(brush, new RectangleF(new PointF(0, 0), page->GetCanvas()->GetSize()));
}

int main()
{
    //创建PdfDocument的对象
    PdfDocument* pdf = new PdfDocument();

    //载入PDF文件
    pdf->LoadFromFile(L"C:/我们之间的距离.pdf");

    //载入图片
    PdfImage* img = PdfImage::FromFile(L"C:/Logo.png");

    //循环遍历文档页面以添加水印
    for (int i = 0; i < pdf->GetPages()->GetCount(); i++) {
        //获取一个页面
        PdfPageBase* page = pdf->GetPages()->GetItem(i);
        //添加水印到页面
        InsertTiledImageWatermark(page, img, 3, 3);
    }

    //保存文档
    pdf->SaveToFile(L"Output/平铺图片水印.pdf");
    pdf->Close();
    delete pdf;
}