PPT97: NewShow Method Doesn't Start Slide Show If Viewer Running

WORKAROUND

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. To work around this problem, use GetObject. If GetObject succeeds (obtains an object reference to PowerPoint Viewer), prompt the user to quit any instances of PowerPoint Viewer. When all instances of PowerPoint Viewer are terminated, use CreateObject to obtain an object reference. The following sample Visual Basic for Applications procedure demonstrates this technique.

    Sub StartShow()

      ' Change the path and file name to specify the presentation
      ' you want to open.
      Const PRESENTATION_NAME As String = "c:\test.ppt"

      ' Used for error trapping.
      On Error Resume Next
      Err.Clear

      ' Declare the variables used in the message box.
      Dim strPrompt As String
      Dim strTitle As String

      ' Declare a variable to store an object reference to PowerPoint
      ' Viewer.
      Dim oViewer As PowerPointViewer.Application

      ' Loop until GetObject fails. GetObject fails when no instances
      ' of PowerPoint Viewer are running.
      Do

         ' Attempt to get a reference to the PowerPoint Viewer
         ' object model. If PowerPoint Viewer is running, GetObject
         ' returns a reference.
         Set oViewer = GetObject(, "PowerPointViewer.Application.8")

         ' If GetObject succeeds, prompt to quit the PowerPoint Viewer.
         If Err.Number = 0 Then

            ' Set up the strings used in the message box.
            strPrompt = "Please quit all instances of Microsoft" _
               & " PowerPoint Viewer 97 " & vbCrLf & "and click retry."
            strTitle = "Quit Viewer 97"

            ' Display the message box.
            Dim lResult As Long
            lResult = MsgBox(strPrompt, vbRetryCancel + vbExclamation, _
               strTitle)

            ' If user clicked Cancel, end the procedure.
            If lResult = vbCancel Then
               Exit Sub
            End If

         End If

      Loop While Err.Number = 0

      ' Reset the Error object if needed.
      If Err.Number <> 0 Then
         Err.Clear
      End If

      ' Launch and get reference to PowerPoint Viewer.
      Set oViewer = CreateObject("PowerPointViewer.Application.8")

      ' Start a presentation in PowerPoint Viewer.
      oViewer.NewShow PRESENTATION_NAME, ppViewerSlideShowManualAdvance, _
         msoTrue

   End Sub