Dim TheCmd As String
Const visOpenRO = 2
Const visOpenMinimized = 16
Const visOpenHidden = 64
Const visOpenMacrosDisabled = 128
Const visOpenNoWorkspace = 256

Sub Main()
    ' interpret command line arguments - separated by spaces outside of double quotes
    TheCmd = Command
    Dim TheCmds() As String
    If SplitCommandArg(TheCmds) Then
        If UBound(TheCmds) > 1 Then
            Dim PageNum As Long
            If UBound(TheCmds) >= 3 Then
                PageNum = Val(TheCmds(3))
            Else
                PageNum = 1
            End If

            ' if the input or output file doesn't contain a file path, then assume the same
            If InStr(1, TheCmds(1),"") = 0 Then
                TheCmds(1) = App.Path &"" & TheCmds(1)
            End If
            If InStr(1, TheCmds(2),"") = 0 Then
                TheCmds(2) = App.Path &"" & TheCmds(2)
            End If

            ConvertVisToImg TheCmds(1), TheCmds(2), PageNum
        Else
            ' no good - need an in and out file
        End If
    End If

End Sub

Function ConvertVisToImg(ByVal InVisPath As String, ByVal OutImgPath As String, PageNum As Long) As Boolean
    ConvertVisToImg = True
    On Error GoTo PROC_ERR

    ' create a new visio instance
    Dim VisApp As Visio.Application
    Set VisApp = CreateObject("Visio.Application")

    ' open invispath
    Dim ConvDoc As Visio.Document
    Set ConvDoc = VisApp.Documents.OpenEx(InVisPath, visOpenRO + visOpenMinimized + visOpenHidden + visOpenMacrosDisabled + visOpenNoWorkspace)

    ' export to outimgpath
    If Not ConvDoc.Pages(PageNum) Is Nothing Then
        ConvDoc.Pages(PageNum).Export OutImgPath
    Else
        MsgBox"Invalid export page"
        ConvertVisToImg = False
        GoTo PROC_END
    End If

    ' close it off
PROC_END:
    On Error Resume Next
    VisApp.Quit
    Set VisApp = Nothing
    Exit Function
PROC_ERR:
    MsgBox Err.Description & vbCr &"Num:" & Err.Number
    GoTo PROC_END
End Function

Function SplitCommandArg(ByRef Commands() As String) As Boolean
    SplitCommandArg = True
    'read through command and break it into an array delimited by space characters only when we're not inside double quotes
    Dim InDblQts As Boolean
    Dim CmdToSplit As String
    CmdToSplit = TheCmd 'for debugging command line parser
    'CmdToSplit = Command
    Dim CharIdx As Integer
    ReDim Commands(1 To 1)
    For CharIdx = 1 To Len(CmdToSplit)
        Dim CurrChar As String
        CurrChar = Mid(CmdToSplit, CharIdx, 1)
        If CurrChar ="" And Not InDblQts Then
            'add another element to the commands array if InDblQts is false
            If Commands(UBound(Commands)) <>"" Then ReDim Preserve Commands(LBound(Commands) To UBound(Commands) + 1)
        ElseIf CurrChar = Chr(34) Then
            'set InDblQts = true
            If Not InDblQts Then InDblQts = True Else InDblQts = False
        Else
            Commands(UBound(Commands)) = Commands(UBound(Commands)) & CurrChar
        End If
    Next CharIdx
End Function

//Description:
// Generates images for all Visio diagrams in folder were run according to pages names
//Tools:
// Visio 2010 32bit is needed to open diagrams (I also installed VisioSDK32bit.exe on my Windows 7 64bit)

#r"C:/Program Files (x86)/Microsoft Visual Studio 10.0/Visual Studio Tools for Office/PIA/Office14/Microsoft.Office.Interop.Visio.dll"

open System
open System.IO

open Microsoft.Office.Interop.Visio

let visOpenRO = 2
let visOpenMinimized = 16
let visOpenHidden = 64
let visOpenMacrosDisabled = 128
let visOpenNoWorkspace = 256

let baseDir = Environment.CurrentDirectory;

let getAllDiagramFiles = Directory.GetFiles(baseDir,"*.vsd")

let drawImage fullPathToDiagramFile =
    let diagrammingApplication = new  ApplicationClass()
    let flags = Convert.ToInt16(visOpenRO + visOpenMinimized + visOpenHidden + visOpenMacrosDisabled + visOpenNoWorkspace)
    let document = diagrammingApplication.Documents.OpenEx(fullPathToDiagramFile,flags)
    for page in document.Pages do
        let imagePath = Path.Combine(baseDir, page.Name +".png")
        page.Export (imagePath)
    document.Close()
    diagrammingApplication.Quit()  

let doItAll =    
    Array.iter drawImage getAllDiagramFiles

doItAll