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Joe OvermanFlag for United States of America

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Accessing/checking the clipboard using MS Access 2003

I am trying to find a way to check if the clipboard has anything on it, without crashing Access in the process.

I am using InternetExplorer application object to access a specific page, paste in certain data, then wait for the results.
I am able to select all and copy the entire page so it can be pasted into MS excel.  From there I pull it into access and use the results.  One problem is that Access moves to fast after the page is loaded and the select all does not happen all the time and when it does the copy does not finish before it needs to be pasted into excel.  So, rather than trap for the error when I try to paste, I want to check to see if the clipboard has anything on it.  I have APIs to get data from the clipboard, send data to the clipboard, and clear the clipboard.  When I try to get the data from the clipboard to check to see if it is blank, Access locks up.   Attached is the code I am using for accessing the clipboard.
Option Compare Database
Option Explicit
 
Declare Function GlobalUnlock Lib "kernel32" (ByVal hMem As Long) _
   As Long
Declare Function GlobalLock Lib "kernel32" (ByVal hMem As Long) _
   As Long
Declare Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Long, _
   ByVal dwBytes As Long) As Long
Declare Function CloseClipboard Lib "User32" () As Long
Declare Function OpenClipboard Lib "User32" (ByVal hwnd As Long) _
   As Long
Declare Function EmptyClipboard Lib "User32" () As Long
Declare Function lstrcpy Lib "kernel32" (ByVal lpString1 As Any, _
   ByVal lpString2 As Any) As Long
Declare Function SetClipboardData Lib "User32" (ByVal wFormat _
   As Long, ByVal hMem As Long) As Long
Declare Function GetClipboardData Lib "User32" (ByVal wFormat As _
   Long) As Long
 
 
Public Const GHND = &H42
Public Const CF_TEXT = 1
Public Const MAXSIZE = 4096
 
Function ClipBoard_SetData(MyString As String)
   Dim hGlobalMemory As Long, lpGlobalMemory As Long
   Dim hClipMemory As Long, X As Long
 
   ' Allocate moveable global memory.
   '-------------------------------------------
   hGlobalMemory = GlobalAlloc(GHND, Len(MyString) + 1)
 
   ' Lock the block to get a far pointer
   ' to this memory.
   lpGlobalMemory = GlobalLock(hGlobalMemory)
 
   ' Copy the string to this global memory.
   lpGlobalMemory = lstrcpy(lpGlobalMemory, MyString)
 
   ' Unlock the memory.
   If GlobalUnlock(hGlobalMemory) <> 0 Then
      MsgBox "Could not unlock memory location. Copy aborted."
      GoTo OutOfHere2
   End If
 
   ' Open the Clipboard to copy data to.
   If OpenClipboard(0&) = 0 Then
      MsgBox "Could not open the Clipboard. Copy aborted."
      Exit Function
   End If
 
   ' Clear the Clipboard.
   X = EmptyClipboard()
 
   ' Copy the data to the Clipboard.
   hClipMemory = SetClipboardData(CF_TEXT, hGlobalMemory)
 
OutOfHere2:
 
   If CloseClipboard() = 0 Then
      MsgBox "Could not close Clipboard."
   End If
End Function
 
Function ClipBoard_GetData()
   Dim hClipMemory As Long
   Dim lpClipMemory As Long
   Dim MyString As String
   Dim RetVal As Long
 
   If OpenClipboard(0&) = 0 Then
      MsgBox "Cannot open Clipboard. Another app. may have it open"
      Exit Function
   End If
         
   ' Obtain the handle to the global memory
   ' block that is referencing the text.
   hClipMemory = GetClipboardData(CF_TEXT)
   If IsNull(hClipMemory) Then
      MsgBox "Could not allocate memory"
      GoTo OutOfHere
   End If
 
   ' Lock Clipboard memory so we can reference
   ' the actual data string.
   lpClipMemory = GlobalLock(hClipMemory)
 
   If Not IsNull(lpClipMemory) Then
      MyString = Space$(MAXSIZE)
      RetVal = lstrcpy(MyString, lpClipMemory)
      RetVal = GlobalUnlock(hClipMemory)
      
      ' Peel off the null terminating character.
      MyString = Mid(MyString, 1, InStr(1, MyString, Chr$(0), 0) - 1)
   Else
      MsgBox "Could not lock memory to copy string from."
   End If
 
OutOfHere:
 
   RetVal = CloseClipboard()
   ClipBoard_GetData = MyString
 
End Function
 
Function ClipBoard_CheckData() As Boolean
   Dim hClipMemory As Long
   Dim lpClipMemory As Long
   Dim MyString As String
   Dim RetVal As Long
 
   If OpenClipboard(0&) = 0 Then
      MsgBox "Cannot open Clipboard. Another app. may have it open"
      Exit Function
   End If
         
   ' Obtain the handle to the global memory
   ' block that is referencing the text.
   hClipMemory = GetClipboardData(CF_TEXT)
   If IsNull(hClipMemory) Then
      MsgBox "Could not allocate memory"
      GoTo OutOfHere
   End If
 
   ' Lock Clipboard memory so we can reference
   ' the actual data string.
   lpClipMemory = GlobalLock(hClipMemory)
 
   If Not IsNull(lpClipMemory) Then
      
      '
      MyString = Space$(MAXSIZE - 5)
      RetVal = GlobalUnlock(hClipMemory)
      If MyString <> "" Then
         RetVal = lstrcpy(MyString, lpClipMemory) ' This line causes a fatal crash.
         ClipBoard_CheckData = True
         'RetVal = CloseClipboard()
         'Exit Function
      Else
         ClipBoard_CheckData = False
      End If
   Else
      MsgBox "Could not lock memory to copy string from."
   End If
 
OutOfHere:
 
   RetVal = CloseClipboard()
   'ClipBoard_GetData = False
End Function

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Chuck Wood
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Joe Overman
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