' UserDefined Error codes
Const ERR_NO_WINDOW_HANDLE As Long = 1000Const ERR_WINDOW_LOCK_FAIL As Long = 1001Const ERR_VERSION_NOT_SUPPORTED As Long = 1002
' API declarations for FindWindow() & LockWindowUpdate()
' Use FindWindow API to locate the PowerPoint handle.
Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, _
ByVal lpWindowName As Long) As Long
' Use LockWindowUpdate to prevent/enable window refresh
Declare Function LockWindowUpdate Lib "user32" _
(ByVal hwndLock As Long) As Long
' Use UpdateWindow to force a refresh of the PowerPoint window
Declare Function UpdateWindow Lib "user32" (ByVal hwnd As Long) As Long
Property Let ScreenUpdating(State As Boolean)
Static hwnd As Long
Dim VersionNo As String
' Get Version Number
If State = False Then
VersionNo = Left(Application.Version, _
InStr(1, Application.Version, ".") - 1)
' Get handle to the main application window using ClassName
Select Case VersionNo
Case "8" ' For PPT97:
hwnd = FindWindow("PP97FrameClass", 0&)
Case "9" ' For PPT2K:
hwnd = FindWindow("PP9FrameClass", 0&)
Case "10" ' For XP:
hwnd = FindWindow("PP10FrameClass", 0&)
Case "11" ' For 2003:
hwnd = FindWindow("PP11FrameClass", 0&)
Case "12" ' For 2007:
hwnd = FindWindow("PP12FrameClass", 0&)
Case Else
Err.Raise Number:=vbObjectError + ERR_VERSION_NOT_SUPPORTED, _
Description:="Supported for PowerPoint 97/2000/2002/2003 only."
Exit Property
End Select
If hwnd = 0 Then
Err.Raise Number:=vbObjectError + ERR_NO_WINDOW_HANDLE, _
Description:="Unable to get the PowerPoint Window handle"
Exit Property
End If
If LockWindowUpdate(hwnd) = 0 Then
Err.Raise Number:=vbObjectError + ERR_WINDOW_LOCK_FAIL, _
Description:="Unable to set a PowerPoint window lock"
Exit Property
End If
Else
' Unlock the Window to refresh
LockWindowUpdate (0&)
UpdateWindow (hwnd)
hwnd = 0
End If
End Property
'Sample Usage:
Sub LongProcessingSub()
' Lock screen redraw
ScreenUpdating=False
' --- Long time consuming code
' Redraw screen again
ScreenUpdating=True
' Also see below article for another example of usage of the code
End Sub
Tags: VBA, Powerpoint, refresh