概述
附件，指随同文件发出的有关文件或物品。在PDF文档中，我们可以添加同类型的或其他类型的文档作为附件内容，而PDF中附件也可以分为两种存在形式，一种是附件以普通文件形式存在，另一种是以注释的形式存在。在下面的示例中介绍了如何分别添加以上两种形式的PDF附件。此外，根据PDF附件的不同添加方式，我们在获取PDF附件信息或删除PDF附件时，也可以分情况来执行操作。
工具使用
代码示例（供参考）
using Spire.Pdf;
using Spire.Pdf.Attachments;
namespace AddAttachment_PDF
{
class Program
{
static void Main(string[] args)
{
//创建一个PdfDocument类对象，加载测试文档
PdfDocument pdf = new PdfDocument();
pdf.LoadFromFile("sample.pdf");
//初始化PdfAttachment类实例，加载需要附加的文档
PdfAttachment attachment = new PdfAttachment("New.pdf");
//将文档添加到原PDF文档的附件集合中
pdf.Attachments.Add(attachment);
//保存并打开文档
pdf.SaveToFile("Attachment1.pdf");
System.Diagnostics.Process.Start("Attachment1.pdf");
}
}
}
测试结果：
using Spire.Pdf;
using Spire.Pdf.Annotations;
using Spire.Pdf.Graphics;
using System;
using System.Drawing;
using System.IO;
namespace AddAttachment2
{
class Program
{
static void Main(string[] args)
{
//创建一个PdfDocument类对象，加载测试文档
PdfDocument doc = new PdfDocument("sample.pdf");
//给添加一个新页面到文档
PdfPageBase page = doc.Pages.Add();
//添加文本到页面，并设置文本格式（字体、题号、字体粗细、颜色、文本位置等）
PdfTrueTypeFont font1 = new PdfTrueTypeFont(new Font("Arial", 16f, System.Drawing.FontStyle.Bold));
page.Canvas.DrawString("Attachments:", font1, PdfBrushes.CornflowerBlue, new Point(50, 50));
//将文档作为注释添加到页面
PdfTrueTypeFont font2 = new PdfTrueTypeFont(new Font("Arial", 12f, System.Drawing.FontStyle.Bold));
PointF location = new PointF(52, 80);
//设置注释标签，标签内容为作为附件的文档
String label = "sample.docx";
byte[] data = File.ReadAllBytes("sample.docx");
SizeF size = font2.MeasureString(label);
//设置注释位置、大小、颜色、标签类型以及显示文本等
RectangleF bounds = new RectangleF(location, size);
page.Canvas.DrawString(label, font2, PdfBrushes.MediumPurple, bounds);
bounds = new RectangleF(bounds.Right + 3, bounds.Top, font2.Height / 2, font2.Height);
PdfAttachmentAnnotation annotation1 = new PdfAttachmentAnnotation(bounds, "sample.docx", data);
annotation1.Color = Color.Purple;
annotation1.Flags = PdfAnnotationFlags.NoZoom;
annotation1.Icon = PdfAttachmentIcon.Graph;
annotation1.Text = "sample.docx";
(page as PdfNewPage).Annotations.Add(annotation1);
//保存并打开文档
doc.SaveToFile("Attachment2.pdf");
System.Diagnostics.Process.Start("Attachment2.pdf");
}
}
}
using Spire.Pdf;
using Spire.Pdf.Attachments;
using System;
using System.IO;
namespace GetAttachment_PDF
{
class Program
{
static void Main(string[] args)
{
//创建PDF文档，加载测试文件
PdfDocument pdf = new PdfDocument();
pdf.LoadFromFile("Attachment1.pdf");
//获取文档中的第一个文件附件
PdfAttachment attachment = pdf.Attachments[0];
//获取该附件的信息
Console.WriteLine("Name: {0}", attachment.FileName);
Console.WriteLine("MimeType: {0}", attachment.MimeType);
Console.WriteLine("Description: {0}", attachment.Description);
Console.WriteLine("Creation Date: {0}", attachment.CreationDate);
Console.WriteLine("Modification Date: {0}", attachment.ModificationDate);
//将附件的数据写入到新文档
File.WriteAllBytes(attachment.FileName, attachment.Data);
Console.ReadKey();
}
}
}
测试结果：
using Spire.Pdf;
using Spire.Pdf.Annotations;
using System.Collections.Generic;
using System.IO;
namespace GetAttachment2
{
class Program
{
static void Main(string[] args)
{
//加载PDF文档
PdfDocument pdf = new PdfDocument();
pdf.LoadFromFile("Attachment2.pdf");
//实例化一个list并将文档内所有页面的Attachment annotations添加到该list
List<PdfAttachmentAnnotationWidget> attaches = new List<PdfAttachmentAnnotationWidget>();
foreach (PdfPageBase page in pdf.Pages)
{
foreach (PdfAnnotation annotation in page.AnnotationsWidget)
{
attaches.Add(annotation as PdfAttachmentAnnotationWidget);
}
}
//遍历list，将附件数据写入到新文档
for (int i = 0; i < attaches.Count; i++)
{
File.WriteAllBytes(attaches[i].FileName, attaches[i].Data);
}
}
}
}
注释附件读取结果：
using Spire.Pdf;
namespace DeleteAttachment_PDF
{
class Program
{
static void Main(string[] args)
{
//加载PDF文档
PdfDocument pdf = new PdfDocument();
pdf.LoadFromFile("Attachment1.pdf");
//删除文档的所有文件附件
for (int i = 0; i < pdf.Attachments.Count; i++)
{
pdf.Attachments.RemoveAt(i);
}
//保存并打开文档
pdf.SaveToFile("Remove.pdf");
System.Diagnostics.Process.Start("Remove.pdf");
}
}
}
using Spire.Pdf;
namespace DeleteAttachment_PDF
{
class Program
{
static void Main(string[] args)
{
//加载PDF文档
PdfDocument pdf = new PdfDocument();
pdf.LoadFromFile("Attachment1.pdf");
//删除文档的所有文件附件
for (int i = 0; i < pdf.Attachments.Count; i++)
{
pdf.Attachments.RemoveAt(i);
}
//保存并打开文档
pdf.SaveToFile("Remove.pdf");
System.Diagnostics.Process.Start("Remove.pdf");
}
}
}
3.2 删除注释附件
using Spire.Pdf;
using Spire.Pdf.Annotations;
namespace DeleteAttachment2
{
class Program
{
static void Main(string[] args)
{
//加载PDF文档
PdfDocument pdf = new PdfDocument();
pdf.LoadFromFile("Attachment2.pdf");
//删除文档的所有注释附件
foreach (PdfPageBase page in pdf.Pages)
{
for (int i = 0; i < page.AnnotationsWidget.Count; i++)
{
PdfAnnotation annotation = page.AnnotationsWidget[i] as PdfAttachmentAnnotationWidget;
page.AnnotationsWidget.Remove(annotation);
}
}
//保存并打开文档
pdf.SaveToFile("Result.pdf");
System.Diagnostics.Process.Start("Result.pdf");
}
}
}
调试程序后，生成的文档就没有附件了。
