'''' This code is part of Document Solutions for PDF .NET demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports System.IOImports System.DrawingImports System.LinqImports System.Collections.GenericImports GrapeCity.Documents.PdfImports GrapeCity.Documents.Pdf.AnnotationsImports GrapeCity.Documents.Pdf.StructureImports GrapeCity.Documents.Pdf.Recognition.Structure
'' Highlight paragraphs which have associated structure tags.Public Class ReadTagsShowParas    Public Function CreatePDF(ByVal stream As Stream) As Integer        Dim user = "DsPdfWeb Demo"
        Dim doc = New GcPdfDocument()        Using s = File.OpenRead(Path.Combine("Resources", "PDFs", "C1Olap-QuickStart.pdf"))            doc.Load(s)
            '' 1st step - remove all but the first 5 pages from the loaded PDF,            ' also removing tags that point to the removed pages:            For i = doc.Pages.Count - 1 To 5 Step -1                RemoveStructNodesForPage(doc.StructTreeRoot.Children, doc.Pages(i))                doc.Pages.RemoveAt(i)            Next
            '' 2nd step - get the logical structure, highlight paragraphs            ' and add sticky notes to them:            Dim ls As LogicalStructure = doc.GetLogicalStructure()            HighlightParagraphs(ls.Elements, user)
            '' Done:            doc.Save(stream)            Return doc.Pages.Count        End Using    End Function
    Private Sub RemoveStructNodesForPage(ses As StructElementCollection, p As Page)        For i = ses.Count - 1 To 0 Step -1            Dim se = ses(i)            If se.DefaultPage Is p Then                ses.RemoveAt(i)            Else                RemoveStructNodesForPage(se.Children, p)            End If        Next    End Sub
    Private Sub HighlightParagraphs(items As IReadOnlyList(Of Element), user As String)        Dim colorVal = Color.FromArgb(64, Color.Magenta)        For Each e In items            If e.HasContentItems Then                For Each i In e.ContentItems                    If TypeOf i Is ContentItem Then                        Dim ci = DirectCast(i, ContentItem)                        Dim p = ci.GetParagraph()                        If p IsNot Nothing Then                            Dim rc = p.GetCoords().ToRect()                            rc.Offset(rc.Width, 0)                            rc.Size = New SizeF(16, 12)                            Dim ta = New TextAnnotation() With {                                .UserName = user,                                .Rect = rc,                                .Page = ci.Page,                                .Contents = p.GetText(),                                .Color = Color.Yellow                            }                            ci.Page.Graphics.DrawPolygon(p.GetCoords(), colorVal)                        End If                    End If                Next            End If            If e.HasChildren Then                HighlightParagraphs(e.Children, user)            End If        Next    End SubEnd Class