PdfDocument.StructureTree Property

Gets the PDF document structure tree.

Namespace: DevExpress.Docs.Pdf

Assembly: DevExpress.Docs.Pdf.v26.1.dll

Declaration

C#

public StructureTree StructureTree { get; }

VB.NET

Public ReadOnly Property StructureTree As StructureTree

Property Value

Type	Description
StructureTree	PDF document structure tree.

Remarks

A tagged PDF document contains a structure tree, a logical representation of the element hierarchy. Assistive technologies, such as screen readers, use the structure tree to identify and navigate document content.

The PdfDocument.StructureTree property returns a PDF document structure tree. Each structure tree node is a StructureElement object. Call the StructureTree.AddChildElement(StructureTypeDescriptor) method to add a child element to the structure tree. The following classes list available type descriptors that you can pass as parameters:

• Pdf17StructureTypeDescriptor - Lists the structure types defined in the PDF 1.7 specification.
• Pdf20StructureTypeDescriptor - Lists the structure types defined in the PDF 2.0 specification.

Example

How to: Create a New Tagged PDF Document

The following code snippet creates a new tagged PDF document.

C#

using DevExpress.Docs.Pdf;
using DevExpress.Drawing.Printing;
using System.Drawing;
using System.IO;

using (PdfDocument document = new PdfDocument())
{
    Page page = document.Pages.Add(DXPaperKind.A4);

    // Create the root Document element.
    StructureElement doc = document.StructureTree
        .AddChildElement(Pdf17StructureType.Document);
    // Add a section to the document.
    StructureElement section =
        doc.AddChildElement(Pdf17StructureType.Sect);

    // Add a heading.
    StructureElement heading =
        section.AddChildElement(Pdf17StructureType.H1);
    heading.AddFragment(page, new TextFragment
    {
        Text = "Invoice",
        Location = new PointF(50, 800),
        Font = new TextFont("Arial", TextFontStyle.Bold),
        FontSize = 24
    });

    // Create a table with layout attributes.
    StructureElement table =
        section.AddChildElement(Pdf17StructureType.Table);
    table.Attributes.Add(new LayoutAttribute
    {
        Placement = LayoutPlacement.Block,
        WritingMode = WritingMode.LeftToRight
    });
    table.Attributes.Add(
        new TableAttribute { Summary = "Invoice items" });
    StructureElement header =
        table.AddChildElement(Pdf17StructureType.THead);
    StructureElement headerRow =
        header.AddChildElement(Pdf17StructureType.TR);

    // Add table header cells.
    StructureElement th1 =
        headerRow.AddChildElement(Pdf17StructureType.TH);
    th1.Attributes.Add(
        new TableAttribute { Scope = TableScope.Column });
    th1.AddFragment(page, new TextFragment
    {
        Text = "Item",
        Location = new PointF(50, 700),
        Font = new TextFont("Arial", TextFontStyle.Bold),
        FontSize = 12
    });

    StructureElement th2 =
        headerRow.AddChildElement(Pdf17StructureType.TH);
    th2.Attributes.Add(
        new TableAttribute { Scope = TableScope.Column });
    th2.AddFragment(page, new TextFragment
    {
        Text = "Qty",
        Location = new PointF(250, 700),
        Font = new TextFont("Arial", TextFontStyle.Bold),
    });

    StructureElement th3 =
        headerRow.AddChildElement(Pdf17StructureType.TH);
    th3.Attributes.Add(
        new TableAttribute { Scope = TableScope.Column });
    th3.AddFragment(page, new TextFragment
    {
        Text = "Price",
        Location = new PointF(320, 700),
        Font = new TextFont("Arial", TextFontStyle.Bold)
    });

    StructureElement th4 =
        headerRow.AddChildElement(Pdf17StructureType.TH);
    th4.Attributes.Add(
        new TableAttribute { Scope = TableScope.Column });
    th4.AddFragment(page, new TextFragment
    {
        Text = "Total",
        Location = new PointF(400, 700),
        Font = new TextFont("Arial", TextFontStyle.Bold),
    });

    // Add table body with a data row.
    StructureElement body =
        table.AddChildElement(Pdf17StructureType.TBody);
    StructureElement dataRow =
        body.AddChildElement(Pdf17StructureType.TR);

    StructureElement td1 =
        dataRow.AddChildElement(Pdf17StructureType.TD);
    td1.AddFragment(page, new TextFragment
    {
        Text = "Product A",
        Location = new PointF(50, 670)
    });

    StructureElement td2 =
        dataRow.AddChildElement(Pdf17StructureType.TD);
    td2.AddFragment(page, new TextFragment
    {
        Text = "2",
        Location = new PointF(250, 670)
    });

    StructureElement td3 =
        dataRow.AddChildElement(Pdf17StructureType.TD);
    td3.AddFragment(page, new TextFragment
    {
        Text = "$25.00",
        Location = new PointF(320, 670)
    });

    StructureElement td4 =
        dataRow.AddChildElement(Pdf17StructureType.TD);
    td4.AddFragment(page, new TextFragment
    {
        Text = "$50.00",
        Location = new PointF(400, 670)
    });

    // Add a paragraph with the total amount.
    StructureElement pTotal =
        section.AddChildElement(Pdf17StructureType.P);
    pTotal.AddFragment(page, new TextFragment
    {
        Text = "Total: $50.00",
        Location = new PointF(50, 620),
        Font = new TextFont("Arial", TextFontStyle.Bold),
    });

    // Save the tagged document.
    using (FileStream stream =
        File.Create("TaggedInvoice.pdf"))
    {
        document.Save(stream);
    }
}

VB.NET

Imports DevExpress.Docs.Pdf
Imports DevExpress.Drawing.Printing
Imports System.Drawing
Imports System.IO

Using document As New PdfDocument()
    Dim page As Page = document.Pages.Add(DXPaperKind.A4)

    ' Create the root Document element.
    Dim doc As StructureElement = document.StructureTree _
        .AddChildElement(Pdf17StructureType.Document)
    ' Add a section to the document.
    Dim section As StructureElement = _
        doc.AddChildElement(Pdf17StructureType.Sect)

    ' Add a heading.
    Dim heading As StructureElement = _
        section.AddChildElement(Pdf17StructureType.H1)
    heading.AddFragment(page, New TextFragment With {
        .Text = "Invoice",
        .Location = New PointF(50, 800),
        .Font = New TextFont("Arial", TextFontStyle.Bold),
        .FontSize = 24
    })

    ' Create a table with layout attributes.
    Dim table As StructureElement = _
        section.AddChildElement(Pdf17StructureType.Table)
    table.Attributes.Add(New LayoutAttribute With {
        .Placement = LayoutPlacement.Block,
        .WritingMode = WritingMode.LeftToRight
    })
    table.Attributes.Add(
        New TableAttribute With {.Summary = "Invoice items"})
    Dim header As StructureElement = _
        table.AddChildElement(Pdf17StructureType.THead)
    Dim headerRow As StructureElement = _
        header.AddChildElement(Pdf17StructureType.TR)

    ' Add table header cells.
    Dim th1 As StructureElement = _
        headerRow.AddChildElement(Pdf17StructureType.TH)
    th1.Attributes.Add(
        New TableAttribute With {.Scope = TableScope.Column})
    th1.AddFragment(page, New TextFragment With {
        .Text = "Item",
        .Location = New PointF(50, 700),
        .Font = New TextFont("Arial", TextFontStyle.Bold),
        .FontSize = 12
    })

    Dim th2 As StructureElement = _
        headerRow.AddChildElement(Pdf17StructureType.TH)
    th2.Attributes.Add(
        New TableAttribute With {.Scope = TableScope.Column})
    th2.AddFragment(page, New TextFragment With {
        .Text = "Qty",
        .Location = New PointF(250, 700),
        .Font = New TextFont("Arial", TextFontStyle.Bold),
        .FontSize = 12
    })

    Dim th3 As StructureElement = _
        headerRow.AddChildElement(Pdf17StructureType.TH)
    th3.Attributes.Add(
        New TableAttribute With {.Scope = TableScope.Column})
    th3.AddFragment(page, New TextFragment With {
        .Text = "Price",
        .Location = New PointF(320, 700),
        .Bold = True
    })

    Dim th4 As StructureElement = _
        headerRow.AddChildElement(Pdf17StructureType.TH)
    th4.Attributes.Add(
        New TableAttribute With {.Scope = TableScope.Column})
    th4.AddFragment(page, New TextFragment With {
        .Text = "Total",
        .Location = New PointF(400, 700),
        .Bold = True
    })

    ' Add table body with a data row.
    Dim body As StructureElement = _
        table.AddChildElement(Pdf17StructureType.TBody)
    Dim dataRow As StructureElement = _
        body.AddChildElement(Pdf17StructureType.TR)

    Dim td1 As StructureElement = _
        dataRow.AddChildElement(Pdf17StructureType.TD)
    td1.AddFragment(page, New TextFragment With {
        .Text = "Product A",
        .Location = New PointF(50, 670)
    })

    Dim td2 As StructureElement = _
        dataRow.AddChildElement(Pdf17StructureType.TD)
    td2.AddFragment(page, New TextFragment With {
        .Text = "2",
        .Location = New PointF(250, 670)
    })

    Dim td3 As StructureElement = _
        dataRow.AddChildElement(Pdf17StructureType.TD)
    td3.AddFragment(page, New TextFragment With {
        .Text = "$25.00",
        .Location = New PointF(320, 670)
    })

    Dim td4 As StructureElement = _
        dataRow.AddChildElement(Pdf17StructureType.TD)
    td4.AddFragment(page, New TextFragment With {
        .Text = "$50.00",
        .Location = New PointF(400, 670)
    })

    ' Add a paragraph with the total amount.
    Dim pTotal As StructureElement = _
        section.AddChildElement(Pdf17StructureType.P)
    pTotal.AddFragment(page, New TextFragment With {
        .Text = "Total: $50.00",
        .Location = New PointF(50, 620),
        .Font = New TextFont("Arial", TextFontStyle.Bold)
    })

    ' Save the tagged document.
    Using stream As FileStream = _
            File.Create("TaggedInvoice.pdf")
        document.Save(stream)
    End Using
End Using