'''' This code is part of Document Solutions for PDF .NET demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports System.IOImports System.DrawingImports GrapeCity.Documents.PdfImports GrapeCity.Documents.Pdf.SecurityImports GrapeCity.Documents.Text
'' This example shows how to load a password protected PDF and try to read its metadata.'' Keep in mind that in some cases metadata in a PDF may also be encrypted, in which case'' reading it without the password is impossible.'' For reference, the loaded PDF is protected with the owner password 'owner' and user password 'user'.Public Class NoPassGetMetadata    Public Function CreatePDF(ByVal stream As Stream) As Integer        Using fs = File.OpenRead(Path.Combine("Resources", "PDFs", "Wetlands-password-user.pdf"))            '' Set up DecryptionOptions to allow loading password protected PDFs without password:            Dim dopt = New DecryptionOptions() With {.ThrowExceptionIfInvalidPassword = False}            Dim docSrc = New GcPdfDocument()            docSrc.Load(fs, dopt)
            '' The PDF to hold the results:            Dim doc = New GcPdfDocument()            Dim page = doc.NewPage()            ' Set up a TextLayout to format the results:            Dim tl = page.Graphics.CreateTextLayout()            tl.DefaultFormat.Font = StandardFonts.Courier            tl.DefaultFormat.FontSize = 14            tl.MaxWidth = doc.PageSize.Width            tl.MaxHeight = doc.PageSize.Height            tl.MarginAll = tl.Resolution            Dim captionFmt = New TextFormat(tl.DefaultFormat) With {.Font = StandardFonts.CourierBold, .FontSize = tl.DefaultFormat.FontSize + 2}
            '' All security handlers before StandardSecurityHandlerRev4 always encrypted metadata,            ' the StandardSecurityHandlerRev4 has EncryptMetadata property which we need to check:            Dim metadataIsEncrypted As Boolean = True            If TypeOf docSrc.Security.EncryptHandler Is StandardSecurityHandlerRev4 Then                Dim ssh = DirectCast(docSrc.Security.EncryptHandler, StandardSecurityHandlerRev4)                metadataIsEncrypted = ssh.EncryptMetadata            End If
            If Not metadataIsEncrypted Then                Dim m As Metadata = docSrc.Metadata                tl.AppendLine("The PDF has unencrypted metadata:", captionFmt)                tl.AppendLine($"  Copyright: {m.Copyright}")                tl.AppendLine($"  CreatorTool: {m.CreatorTool}")                If m.CreateDate.HasValue Then                    tl.AppendLine($"  CreateDate: {m.CreateDate.Value.ToUniversalTime():R}")                End If                tl.AppendLine($"  Description: {m.Description}")                If m.ModifyDate.HasValue Then                    tl.AppendLine($"  ModifyDate: {m.ModifyDate.Value.ToUniversalTime():R}")                End If                tl.AppendLine($"  Producer: {m.Producer}")                tl.AppendLine($"  Title: {m.Title}")            Else                tl.AppendLine("Cannot read metadata because the PDF metadata is encrypted.", captionFmt)            End If
            '' Render the results:            tl.PerformLayout(True)            While True                Dim rest As TextLayout = Nothing                Dim splitResult = tl.Split(Nothing, rest)                page.Graphics.DrawTextLayout(tl, PointF.Empty)                If splitResult <> SplitResult.Split Then                    Exit While                End If                tl = rest                tl.MarginTop = tl.Resolution                page = doc.Pages.Add()            End While
            '' Done:            doc.Save(stream)            Return doc.Pages.Count        End Using    End FunctionEnd Class