C#/VB.NET 创建PDF/UA文件

傷城~ 2023-10-11 18:17 14阅读 0赞

## 1.什么是PDF/UA文件 ##

PDF/UA，即Universally Accessible PDF，该格式的PDF文件是于2012年8月以ISO标准14289-1发布的、具有普遍可访问的PDF文档标准。为带标签的PDF文档（Tagged PDF Document）和表单的开发人员和作者设定了明确的规则。（PDF/UA-1是作为PDF/UA标准的第一部分，PDF/UA-2作为PDF/UA标准的第二部分）\[1\]

## 2.文件格式要求 ##

PDF/UA在其基础上有着明确的要求，即该标准都是基于PDF标签，所有PDF/UA文档都必须以PDF标签来正确标记，并且，要求标签在语义上适当，并按逻辑顺序排列。\[1\]

## 3.如何创建PDF/UA文件 ##

PDF/UA文件作为PDF文件的一种标准格式，要创建该标准的的PDF文档，可使用调用PDF API的方法来创建。下面，是以Spire.PDF for .NET来创建的方法。

**注：**可在Visual Studio 中通过[NuGet][]搜索“Spire.PDF”安装dll到程序中；

或者下载[包][Link 1]（hotfix版本）到本地，手动添加本地路径下的Spire.Pdf.dll文件到程序。

C\#

using Spire.Pdf;
    using Spire.Pdf.Graphics;
    using Spire.Pdf.Interchange.TaggedPdf;
    using System.Drawing;
    namespace CreatePDFUAfile
    {
     class Program
        {
     static void Main(string[] args)
            {
                //创建PdfDocument类的对象
                PdfDocument doc = new PdfDocument();
    
                 //添加一页
                doc.Pages.Add();
    
                 //设置tab order
                doc.Pages[0].SetTabOrder(TabOrder.Structure);
    
                 //创建PdfTaggedContent类的对象
                PdfTaggedContent taggedContent = new PdfTaggedContent(doc);
                taggedContent.SetLanguage("en-US");
                taggedContent.SetTitle("test");
    
                 //设置PDF/UA1验证
                taggedContent.SetPdfUA1Identification();
    
                 //创建字体、画刷
                PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Times New Roman", 10), true);
                PdfSolidBrush brush = new PdfSolidBrush(Color.Black);
    
                 //添加要素
                PdfStructureElement article = taggedContent.StructureTreeRoot.AppendChildElement(PdfStandardStructTypes.Document);
                PdfStructureElement paragraph1 = article.AppendChildElement(PdfStandardStructTypes.Paragraph);
                PdfStructureElement span1 = paragraph1.AppendChildElement(PdfStandardStructTypes.Span);
                span1.BeginMarkedContent(doc.Pages[0]);
                PdfStringFormat format = new PdfStringFormat(PdfTextAlignment.Justify);
                doc.Pages[0].Canvas.DrawString("PDF/UA was published as ISO Standard 14289-1 in August 2012" +
     " and is by far the first complete definition " +
     "of a set of requirements for universally accessible PDF documents.",
                   font, brush, new Rectangle(40, 80, 450, 80), format);
                span1.EndMarkedContent(doc.Pages[0]);
                PdfStructureElement paragraph2 = article.AppendChildElement(PdfStandardStructTypes.Paragraph);
                paragraph2.BeginMarkedContent(doc.Pages[0]);
                doc.Pages[0].Canvas.DrawString("The PDF/UA has some definite requirements at its base that act as the essence of this standard.",
                   font, brush, new Rectangle(40, 120, 450, 60), format);
                paragraph2.EndMarkedContent(doc.Pages[0]);
                PdfStructureElement figure1 = article.AppendChildElement(PdfStandardStructTypes.Figure);
                 //Set Alternate text 
                figure1.Alt = "replacement text1";
                figure1.BeginMarkedContent(doc.Pages[0], null);
                PdfImage image = PdfImage.FromFile(@"logo.jpg");
                doc.Pages[0].Canvas.DrawImage(image, new PointF(40, 200), new SizeF(100, 100));
                figure1.EndMarkedContent(doc.Pages[0]);
                PdfStructureElement figure2 = article.AppendChildElement(PdfStandardStructTypes.Figure);
                 //Set Alternate text
                figure2.Alt = "replacement text2";
                figure2.BeginMarkedContent(doc.Pages[0], null);
                doc.Pages[0].Canvas.DrawRectangle(PdfPens.Black, new Rectangle(300, 200, 100, 100));
                figure2.EndMarkedContent(doc.Pages[0]);
                 //保存文档
                doc.SaveToFile("CreatePDFUAFile_result.pdf");
                System.Diagnostics.Process.Start("CreatePDFUAFile_result.pdf");
            }
        }
    }

VB.NET

Imports Spire.Pdf
    Imports Spire.Pdf.Graphics
    Imports Spire.Pdf.Interchange.TaggedPdf
    Imports System.Drawing
    
    Namespace CreatePDFUAfile
    	Class Program
    		Private Shared Sub Main(args As String())
    			'创建PdfDocument类的对象
    			Dim doc As New PdfDocument()
    
    			'添加一页
    			doc.Pages.Add()
    
    			'设置tab order
    			doc.Pages(0).SetTabOrder(TabOrder.[Structure])
    
    			'创建PdfTaggedContent类的对象
    			Dim taggedContent As New PdfTaggedContent(doc)
    			taggedContent.SetLanguage("en-US")
    			taggedContent.SetTitle("test")
    
    			'设置PDF/UA1验证
    			taggedContent.SetPdfUA1Identification()
    
    			'创建字体、画刷
    			Dim font As New PdfTrueTypeFont(New Font("Times New Roman", 10), True)
    			Dim brush As New PdfSolidBrush(Color.Black)
    
    			'添加要素
    			Dim article As PdfStructureElement = taggedContent.StructureTreeRoot.AppendChildElement(PdfStandardStructTypes.Document)
    			Dim paragraph1 As PdfStructureElement = article.AppendChildElement(PdfStandardStructTypes.Paragraph)
    			Dim span1 As PdfStructureElement = paragraph1.AppendChildElement(PdfStandardStructTypes.Span)
    			span1.BeginMarkedContent(doc.Pages(0))
    
    			Dim format As New PdfStringFormat(PdfTextAlignment.Justify)
    			doc.Pages(0).Canvas.DrawString("PDF/UA was published as ISO Standard 14289-1 in August 2012" + " and is by far the first complete definition " + "of a set of requirements for universally accessible PDF documents.", font, brush, New Rectangle(40, 80, 450, 80), format)
    			span1.EndMarkedContent(doc.Pages(0))
    
    			Dim paragraph2 As PdfStructureElement = article.AppendChildElement(PdfStandardStructTypes.Paragraph)
    			paragraph2.BeginMarkedContent(doc.Pages(0))
    			doc.Pages(0).Canvas.DrawString("The PDF/UA has some definite requirements at its base that act as the essence of this standard.", font, brush, New Rectangle(40, 120, 450, 60), format)
    			paragraph2.EndMarkedContent(doc.Pages(0))
    
    			Dim figure1 As PdfStructureElement = article.AppendChildElement(PdfStandardStructTypes.Figure)
    			'Set Alternate text 
    			figure1.Alt = "replacement text1"
    			figure1.BeginMarkedContent(doc.Pages(0), Nothing)
    			Dim image As PdfImage = PdfImage.FromFile("logo.jpg")
    			doc.Pages(0).Canvas.DrawImage(image, New PointF(40, 200), New SizeF(100, 100))
    			figure1.EndMarkedContent(doc.Pages(0))
    
    			Dim figure2 As PdfStructureElement = article.AppendChildElement(PdfStandardStructTypes.Figure)
    			'Set Alternate text
    			figure2.Alt = "replacement text2"
    			figure2.BeginMarkedContent(doc.Pages(0), Nothing)
    			doc.Pages(0).Canvas.DrawRectangle(PdfPens.Black, New Rectangle(300, 200, 100, 100))
    			figure2.EndMarkedContent(doc.Pages(0))
    
    			'保存文档
    			doc.SaveToFile("CreatePDFUAFile_result.pdf")
    			System.Diagnostics.Process.Start("CreatePDFUAFile_result.pdf")
    		End Sub
    	End Class
    End Namespace

![05413cd6c48e4a87bd581fd590f45861.jpeg][]

参考资料：

1.  [PDF/UA File Format][PDF_UA File Format]

—END—

**相关阅读推荐：**[C\# 创建标签PDF文件][C_ _PDF]

[NuGet]: https://www.nuget.org/packages/Spire.PDF
[Link 1]: https://www.e-iceblue.cn/Downloads/Spire-PDF-NET.html
[05413cd6c48e4a87bd581fd590f45861.jpeg]: https://img-blog.csdnimg.cn/05413cd6c48e4a87bd581fd590f45861.jpeg
[PDF_UA File Format]: https://docs.fileformat.com/pdf/ua/
[C_ _PDF]: https://blog.csdn.net/Eiceblue/article/details/126361696