'''' 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.Annotations
'' This example shows how to load a password protected PDF without specifying the password,'' and add a square annotation (a red border along the sides of the page) to the first page of the PDF.'' The modified PDF is saved and re-opened with the password so that we can show it in the demo.Public Class NoPassAddAnnotation    Public Function CreatePDF(ByVal stream As Stream) As Integer        Using fsSrc = 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(fsSrc, dopt)
            '' Add a square annotation to the first page of the PDF:            Dim page = docSrc.Pages(0)            Dim pageSize = page.Size            Dim sa = New SquareAnnotation() With {                .Page = page,                .Rect = New RectangleF(36, 36, pageSize.Width - 72, pageSize.Height - 72),                .Color = Color.Red            }            ' Note: we must remove the UserName, as it is initialized by default which will cause an exception            ' when the document is saved, because strings cannot be encrypted:            sa.UserName = Nothing
            '' Demo site specific:            ' We save the modified password protected document to a temp file,            ' and load it again with the password, so that the demo site can show it            ' without asking the user for a password:            Dim fn = Path.GetTempFileName()            docSrc.Save(fn)            Dim doc = New GcPdfDocument()            Using fs = File.OpenRead(fn)                doc.Load(fs, "user")                doc.Save(stream)            End Using            File.Delete(fn)            '' Done:            Return docSrc.Pages.Count        End Using    End FunctionEnd Class