'''' This code is part of Document Solutions for PDF .NET demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports System.IOImports System.DrawingImports System.Collections.GenericImports GrapeCity.Documents.CommonImports GrapeCity.Documents.PdfImports GrapeCity.Documents.Pdf.Layers
Public Class SearchInLayers    Public Function CreatePDF(ByVal stream As Stream) As Integer        Using fs = File.OpenRead(Path.Combine("Resources", "PDFs", "lang-layers.pdf"))            Dim doc = New GcPdfDocument()            doc.Load(fs)
            Dim regex = "\b(Windows|macOS|Linux|Mac)\b"            FindInLayer(doc, "English", regex, Color.FromArgb(100, Color.Red))            FindInLayer(doc, "French", regex, Color.FromArgb(100, Color.Blue))            FindInLayer(doc, "Russian", regex, Color.FromArgb(100, Color.Green))
            ' Save the PDF:            doc.Save(stream)            Return doc.Pages.Count        End Using    End Function
    Private Shared Sub FindInLayer(doc As GcPdfDocument, layer As String, text As String, highlight As Color)        ' Create a view state with just the specified layer visible:        Dim viewState = New ViewState(doc)        viewState.SetLayersUIStateExcept(False, layer)        viewState.SetLayersUIState(True, layer)
        ' Create a FindTextParams using our custom view state        ' so that the search is limited to the specified layer only:        Dim ftp = New FindTextParams(text, False, False, viewState, 72.0F, 72.0F, True, True)
        ' Find all occurrences of the search text:        Dim finds = doc.FindText(ftp, OutputRange.All)
        ' Highlight all occurrences on the specified layer only:        For Each find In finds            For Each ql In find.Bounds                Dim g = doc.Pages(find.PageIndex).Graphics                g.BeginLayer(layer)                doc.Pages(find.PageIndex).Graphics.FillPolygon(ql, highlight)                g.EndLayer()            Next        Next    End SubEnd Class