- A+
所属分类：.NET技术
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（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
参考资料：
—END—
相关阅读推荐：C# 创建标签PDF文件
