C#C# 添加、获取及删除PDF附件

C# 拉长、获取及删除PDF附件

前言

附件在PDF文档中很常见,这一个附件可以是PDF或其它品类的文书。在PDF中,附件有三种存在形式,一种是平常的公文附件(document-level
file
attachment),另一种是注释(annotation)。本文主要介绍怎么着在C#应用程序中给PDF文档添加附件以及从PDF文档获取附件、删除附件。

大家都知道.NET Framework
本人并不曾一直操作PDF的类库,因而在.NET应用程序中操作PDF文档必须求借助第三方组件提供的dll。本文首要运用的是Free
Spire.PDF组件的dll。

实现

1.  添加附件

以下代码将介绍二种将文档附加到PDF的章程。一种是将文档作为文件附件添加到PDF,另一种则是将文档作为注释附加到PDF的页面中。

1.1  将文档作为文件附件添加到PDF

该措施是透过调用PdfAttachmentCollection类的Add()方法将文档添加到PdfDocument对象的Attachments集合中。

//加载PDF文档
PdfDocument pdf = new PdfDocument("Test.pdf");

//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);

//保存文档
pdf.SaveToFile("Attachment1.pdf");

 C# 1                     

1.2  将文档作为注释(annotation)附加到PDF文档的页面

成立注释时,大家需求利用以下类PdfAttachmentAnnotation:

namespace Spire.Pdf.Annotations
{
    // Summary:
    //     Represents an attachment annotation.
    public class PdfAttachmentAnnotation : PdfFileAnnotation
    {
        //
        // Parameters:
        //   rectangle:
        //     Bounds of the annotation.
        //
        //   fileName:
        //     A string value specifying the full path to the file to be embedded in the
        //     PDF file.
        public PdfAttachmentAnnotation(RectangleF rectangle, string fileName);
        //
        //
        // Parameters:
        //   rectangle:
        //     Bounds of the annotation.
        //
        //   fileName:
        //     A string value specifying the full path to the file to be embedded in the
        //     PDF file.
        //
        //   data:
        //     A byte array specifying the content of the annotation's embedded file.
        //
        // Remarks:
        //     If both FileName and FileContent are specified, the FileContent takes precedence.
        public PdfAttachmentAnnotation(RectangleF rectangle, string fileName, byte[] data);
        //
        //
        // Parameters:
        //   rectangle:
        //     The rectangle.
        //
        //   fileName:
        //     A string value specifying the full path to the file to be embedded in the
        //     PDF file.
        //
        //   stream:
        //     The stream specifying the content of the annotation's embedded file.
        //
        // Remarks:
        //     If both FileName and FileContent are specified, the FileContent takes precedence.
        public PdfAttachmentAnnotation(RectangleF rectangle, string fileName, Stream stream);

        public override string FileName { get; set; }
        //
        // Summary:
        //     Gets or Sets attachment's icon.
        public PdfAttachmentIcon Icon { get; set; }

        protected override void Initialize();
        protected override void Save();
    }
}

 代码段:

//加载PDF文档
PdfDocument doc = new PdfDocument("Test.pdf");

//给文档添加一个新页面
PdfPageBase page = doc.Pages.Add();

//添加文本到页面
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);
String label = "Report.docx";
byte[] data = File.ReadAllBytes("Report.docx");
SizeF size = font2.MeasureString(label);
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, "Report.docx", data);
annotation1.Color = Color.Purple;
annotation1.Flags = PdfAnnotationFlags.NoZoom;
annotation1.Icon = PdfAttachmentIcon.Graph;
annotation1.Text = "Report.docx";
(page as PdfNewPage).Annotations.Add(annotation1);

//保存文档
doc.SaveToFile("Attachment2.pdf");

C# 2
 

2.  赢得附件

依照附件添加形式的两样,获取附件也分为以下三种相应的法门。

2.1  赢得文件附件

收获文件附件时,大家还是可以取得附件的消息如文件名,MimeType,描述,成立日期和修改日期等。

//加载PDF文档
PdfDocument pdf = new PdfDocument("Attachment1.pdf");

//获取文档的第一个文件附件
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();

C# 3 

2.2  获取注释附件

//加载PDF文档
PdfDocument pdf = new PdfDocument("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);
}

 

3.  去除附件

3.1  除去文件附件

//加载PDF文档
PdfDocument pdf = new PdfDocument("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);
} 

//保存文档
pdf.SaveToFile("Remove.pdf");

 

3.2  删除注释附件

//加载PDF文档
PdfDocument pdf = new PdfDocument("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);                   
    }
}

//保存文档
pdf.SaveToFile("Result.pdf");

 

总结:

本文只对该dll的局地机能做了简短的牵线,若是需求了然更加多内容,可以去官网NuGet下载dll举行测试。

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