主题：如何调用Spire.PDF.dll给PDF加印章？

using Spire.Pdf;

using Spire.Pdf.Annotations;

using Spire.Pdf.Annotations.Appearance;

using Spire.Pdf.Graphics;

using System;

using System.Drawing;

namespace AddStamp_PDF

{

class Program

{

static void Main(string[] args)

{

//创建一个PdfDocument类对象，并加载PDF文档

PdfDocument doc = new PdfDocument();

doc.LoadFromFile(@"C:\Users\Administrator\Desktop\test.pdf");

//获取PDF文档第一页

PdfPageBase page = doc.Pages[0];

//新建一个PdfRubberStampAnnotation对象，指定其注释的位置和大小

PdfRubberStampAnnotation loStamp = new PdfRubberStampAnnotation(new RectangleF(new PointF(-5, -5), new SizeF(200, 200)));

//实例化一个PdfAppearance对象，并加载作为印章的图片

PdfAppearance loApprearance = new PdfAppearance(loStamp);

PdfImage image = PdfImage.FromFile(@"C:\Users\Administrator\Desktop\yz.jpg");

//新建一个PDF模板，并在模板里绘制图片

PdfTemplate template = new PdfTemplate(600, 800);

template.Graphics.DrawImage(image, 0, 0);

loApprearance.Normal = template;

loStamp.Appearance = loApprearance;

//添加印章到PDF文档

page.AnnotationsWidget.Add(loStamp);

//保存并打开文档

string output = "ImageStamp.pdf";

doc.SaveToFile(output);

System.Diagnostics.Process.Start("ImageStamp.pdf");

}

}

}