Export Page Layout to PDF using ESRI add-in with vb.net

Note: This message is cross-posted on geonet (http://ift.tt/1CQvNd2)

I have been trying to convert a vba script to vb.net but I have hit a roadblock and I'm hoping someone can help me figure out the problem. I want to export the Page Layout of my map to a PDF using an add-in button. The roadblock occurs where I define my PDFCreate class. I keep receiving the error message:

"Unable to cast object of type 'CreatePDF_2.PDFCreate' to type ESRI.ArcGIS.Output.IExport".

I suspect the error is in my definition and relationship of the document, active view and page layout. I have looked at examples and tried different definitions and procedures but I have been unable to figure out how to fix the problem.

I am using Visual Studio 2010 Professional and ArcMap 10.2.2

Any assistance will be appreciated.

Code updated on March 26th. User input for save file option not working. I am trying to design it so that the user will see a windows form and can specify the file path and file name. People will be using the button on a regular basis with the same map and saving to the same folder but with a different layout view. Hence the name needs to be specified at the time of creation. Creating the button this way (instead of using the already available export option) will eliminate 2 extra steps for the users.

Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Geometry
Imports System.Windows.Forms
Imports ESRI.ArcGIS.Output
Imports ESRI.ArcGIS.ArcMapUI

Public Class PDFCreation
    Inherits ESRI.ArcGIS.Desktop.AddIns.Button

    Protected Overrides Sub OnClick()
        '
        '  TODO: Sample code showing how to access button host
        '
    PDFModule()

    End Sub

    Protected Overrides Sub OnUpdate()

        Enabled = My.ArcMap.Application IsNot Nothing
    End Sub

    Public Sub PDFModule()

        Dim pMxDoc As IMxDocument
        Dim pActiveView As IActiveView
        Dim pPageLayout As IPageLayout
        Dim pExport As IExport
        Dim pPixelEnv As IEnvelope
        Dim lDPI As Long
        Dim tExpRect As tagRECT
        Dim hDC As Long
        Dim res = 96

        pMxDoc = My.ArcMap.Application.Document
        pPageLayout = pMxDoc.PageLayout
        pActiveView = pPageLayout

        pExport = New ESRI.ArcGIS.Output.ExportPDF
        pPixelEnv = New Envelope

        lDPI = 300
        pExport.Resolution = lDPI

        tExpRect.left = 0
        tExpRect.top = 0
        tExpRect.bottom = My.ArcMap.Document.ActiveView.ExportFrame.bottom * (lDPI / res)
        tExpRect.right = My.ArcMap.Document.ActiveView.ExportFrame.right * (lDPI / res)

        pPixelEnv.PutCoords(tExpRect.left, tExpRect.top, tExpRect.right, tExpRect.bottom)
        pExport.PixelBounds = pPixelEnv

        Dim pdfName As String = ""
        Dim saveFileDialog1 As New SaveFileDialog
        saveFileDialog1.Filter = "PDF File|*.pdf"
        saveFileDialog1.Title = "Save A PDF File"
        saveFileDialog1.FileName = pdfName
        'Dim dr As System.Windows.Forms.DialogResult
        saveFileDialog1.ShowDialog()

        'If (dr = System.Windows.Forms.DialogResult.OK) 
        '    {   string pdfFlFullName = strOutPut.FileName
        '    pdfFlPath = System.IO.Path.GetDirectoryName(pdfFlFullName)
        '        }
        'Else
        '    pdfFlPath = @"C:\temp"

        hDC = pExport.StartExporting
        pActiveView.Output(hDC, lDPI, tExpRect, Nothing, Nothing)
        pExport.FinishExporting()

        MessageBox.Show("Finished Exporting Map")

        pExport.Cleanup()
    End Sub
End Class

Here is my code incorporating the coding used in the ESRI active page layout pdf export code snippet. I comment out pExportpdf and instead use ExportPDF in Select Case and change pExportpdf.EmbedFonts to pExport.EmbedFonts. I include Dim ExportPDF as String.

When I use this method, I receive the error message:

Implementing class ‘ESRI.ArcGIS.Output.ExportPDFClass’ for interface 'ESRI.ArcGIS.Output.ExportPDF’ cannot be found.

Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Geometry
Imports ESRI.ArcGIS.Output
Imports System.Windows.Forms
Imports ESRI.ArcGIS.ArcMapUI

Public Class PDFCreate
    Inherits ESRI.ArcGIS.Desktop.AddIns.Button

    Public Sub New()

    End Sub

    Protected Overrides Sub OnClick()

        PDFCreatemodule()

    End Sub


    Protected Overrides Sub OnUpdate()

        Enabled = My.ArcMap.Application IsNot Nothing
    End Sub

    Public Sub PDFCreatemodule()
        '
        '  TODO: Sample code showing how to access button host
        '
        Dim pMxDoc As IMxDocument
        Dim pActiveView As IActiveView
        Dim pPageLayout As IPageLayout
        Dim pExport As ESRI.ArcGIS.Output.IExport
        'Dim pExportpdf As ESRI.ArcGIS.Output.IExportPDF
        Dim pPixelEnv As IEnvelope
        Dim lDPI As Long
        Dim tExpRect As tagRECT
        Dim hDC As Long
        Dim ExportFormat As String

        'pMxApp = Application
        pMxDoc = My.ArcMap.Application.Document
        pActiveView = pMxDoc.PageLayout
        pPageLayout = pMxDoc.PageLayout
        pActiveView = pPageLayout

        pExport = New PDFCreate
        'pExportpdf = pExport

        Select Case ExportFormat
            Case "PDF"
                pExport = New ExportPDF
        End Select

        pPixelEnv = New Envelope

        pExport.ExportFileName = " " & ".pdf"
        pExport.Resolution = lDPI

        pExport.EmbedFonts = True

        pPixelEnv.PutCoords(0, 0, lDPI * PageExtent(pPageLayout).UpperRight.X, _
                              lDPI * PageExtent(pPageLayout).UpperRight.Y)
        pExport.PixelBounds = pPixelEnv

        ' (device coordinates origin is upper left, ypositive is down)
        tExpRect.left = pExport.PixelBounds.LowerLeft.X
        tExpRect.bottom = pExport.PixelBounds.UpperRight.Y
        tExpRect.right = pExport.PixelBounds.UpperRight.X
        tExpRect.top = pExport.PixelBounds.LowerLeft.Y

        hDC = pExport.StartExporting
        pActiveView.Output(hDC, lDPI, tExpRect, Nothing, Nothing)
        System.Windows.Forms.Application.DoEvents()
        pExport.FinishExporting()

    End Sub

    Public Function PageExtent(pPageLayout) As IEnvelope
        Dim dWidth As Double, dHeight As Double
        pPageLayout.Page.QuerySize(dWidth, dHeight)
        Dim pEnv As IEnvelope
        pEnv = New Envelope
        pEnv.PutCoords(0.0#, 0.0#, dWidth, dHeight)
        PageExtent = pEnv
    End Function

End Class

This is an error message I am receiving...