Function that exports (single page) visio diagram as png, and remembers sequence number in windows registry

gistfile1.bas

Sub ExportPNG()

  Dim formatExtension As String
  formatExtension = ".png"
  '//…or .bmp, .jpg, .png, .tif

  '// Init folder, doc and counter:
  folder = ThisDocument.Path & "Workshop1"
  Set doc = Visio.ActiveDocument
  
  ' Create variables.
  Dim sAppName As String
  Dim sSection As String
  Dim sKey As String
  Dim sFieldName As String
  Dim lRegValue As Long
  Dim extNumber As String
  Dim iDefault As Integer
  sAppName = "Visio 2010"
  sSection = "DSE"
  sKey = "Workshop1 Presentation Image Number"

  ' The default starting number.
  iDefault = 1

  ' If the specified form field doesn't exist,
  ' an error will occur.
  On Error GoTo Errhandler

  ' Get stored registry value, if any.
  lRegValue = GetSetting(sAppName, sSection, sKey, iDefault)
  ' If the result is zero, set to default value.
  If lRegValue = 0 Then lRegValue = iDefault

  ' Increment and update invoice number.
  SaveSetting sAppName, sSection, sKey, lRegValue + 1

  '// Loop through pages:
  For Each pg In doc.Pages

    '// Setup the filename:
    extNumber = Format(lRegValue, "000")
    FileName = "slide" & extNumber

    '// Append '(bkgnd)' to background pages:
    If (pg.Background) Then FileName = FileName & " (bkgnd)"

    '// Add the extension:
    FileName = FileName & formatExtension

    '// Save it:
    Call pg.Export(folder & FileName)

  Next

Errhandler:

   If Err <> 0 Then
      MsgBox Err.Description
   End If

End Sub

One should do a manual export first to establish the parameters of the PNG file (transparency, depth, etc.)