I am trying to create PDFs with header and footer using Powershell. I am using PowerShell v5.1. My PowerShell experience is pretty rudimentary as I usually do coding in C#/VB. Unfortunately, one of the requirements is to do this in PowerShell. The library I am using is iTextSharp library.

I am including iTextSharp.dll in my script

Add-Type -Path "$ScriptLocationIncludesitextsharp.dll" -ErrorAction Stop

I need to inherit the iTextSharp.text.pdf.PdfPageEventHelper class to override the OnEndPage function. Everytime I load the script into PowerShell ISE environment, I get this error: Unable to find the type [iTextSharp.text.pdf.PdfPageEventHelper]. However, the ‘missing’ type is part of the itextsharp.dll.

I am able to get the environment to recognize the type after the following steps:

1. Comment out the inherited class and the command
2. Run the script
3. Uncomment the inherit class and function

In VB.NET, it has the imports statement, sometime like this:

Imports iTextSharp.text

Is there something similar in Powershell? How can I force the PowerShell environment to recongnize the sub class (iTextSharp.text) without going through those steps I outlinged above?

My code is as follows:

Add-Type -Path "$ScriptLocationIncludesitextsharp.dll" -ErrorAction Stop

    class PdfPageEvents : iTextSharp.text.pdf.PdfPageEventHelper {
        [string]$headerText
    
        PdfPageEvents([string]$headerText) {
            $this.headerText = $headerText
        }
    
        
        # Override OnEndPage to add header and footer
        [void] OnEndPage ([iTextSharp.text.pdf.PdfWriter]$writer, [iTextSharp.text.Document]$document) {
            $cb = $writer.DirectContent
            $pageSize = $document.PageSize
    
            # Add header
            $header = New-Object iTextSharp.text.Paragraph($this.headerText, New-Object iTextSharp.text.Font([iTextSharp.text.Font]::ARIAL, 12))
            $header.Alignment = [iTextSharp.text.Element]::ALIGN_CENTER
            $headerTable = New-Object iTextSharp.text.pdf.PdfPTable(1)
            $headerTable.TotalWidth = $pageSize.Width - $document.LeftMargin - $document.RightMargin
            $headerTable.AddCell($header)
            $headerTable.WriteSelectedRows(0, -1, $document.LeftMargin, $pageSize.Height - $document.TopMargin + 15, $cb)
   
        }
    }
    
    $pdfDocument = New-Object iTextSharp.text.Document([iTextSharp.text.Rectangle]::new([iTextSharp.text.PageSize]::A4.Height, [iTextSharp.text.PageSize]::A4.Width))
                
    $fileStream = New-Object -TypeName IO.FileStream -ArgumentList ($FileOutputName, [System.IO.FileMode]::Create)
    $pdfWriter = [iTextSharp.text.pdf.PdfWriter]::GetInstance($pdfDocument, $filestream)
    [iTextSharp.text.FontFactory]::RegisterDirectories()
    $pdfDocument.Open()
    $paragraph = New-Object -TypeName iTextSharp.text.Paragraph
    
    $headerString = "Header Text"
    $pdfWriter.PageEvent = [PdfPageEvents]::new("$headerString")
    $paragraph.add("blah blah blah")
    $pdfDocument.Add($paragraph)
    $pdfDocument.Close()