'''' This code is part of Document Solutions for PDF .NET demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports System.IOImports System.Collections.GenericImports GrapeCity.Documents.Pdf
Public Class HousePlanLayers    Public Function CreatePDF(ByVal stream As Stream) As Integer        ' The list of PDF names' parts identifying their semantics:        Dim fnames As String() = {            "full_electrical_plan.pdf",            "all_outlets.pdf",            "data_plan_and_detectors.pdf",            "HVAC_with_wiring.pdf",            "lighting_plan.pdf",            "lighting_plan_with_wiring.pdf",            "security_system_plan.pdf"        }        ' The common base name:        Dim fbase = "how_to_read_electrical_plans_"        ' The directory containing the PDFs:        Dim dir = Path.Combine("Resources", "PDFs")
        Dim doc As GcPdfDocument = Nothing        Dim page As Page = Nothing        Dim g As GcPdfGraphics = Nothing        Dim disposables = New List(Of IDisposable)()        ' Combine all PDFs into a single document.        ' The first PDF is used as the base,        ' additional PDFs are added as optional content (layers):        For i = 0 To fnames.Length - 1            Dim iname = fnames(i)            Dim idoc = New GcPdfDocument()            Dim ifs = File.OpenRead(Path.Combine(dir, fbase & iname))            idoc.Load(ifs)            disposables.Add(ifs)            If i = 0 Then                doc = idoc                page = idoc.Pages.Last                g = page.Graphics            Else                doc.OptionalContent.AddLayer(iname)                doc.OptionalContent.SetLayerDefaultState(iname, False)                g.BeginLayer(iname)                g.DrawPdfPage(idoc.Pages(0), page.Bounds)                g.EndLayer()            End If        Next        ' Save the PDF:        doc.Save(stream)
        ' Dispose file streams:        disposables.ForEach(Sub(d_) d_.Dispose())        Return doc.Pages.Count    End FunctionEnd Class