PRB: MSFLexGrid Redraw May Not Function Correctly

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 6.0

SYMPTOMS

After setting the TopRow property of the MSFlexGrid, setting the Redraw property to True does not cause the MSFlexGrid to be automatically redrawn.

CAUSE

Microsoft is researching this problem and will post new information in the Microsoft Knowledge Base as it becomes available.

RESOLUTION

There are a couple of workarounds to this problem. You can use the code in these workarounds in place of the code shown in the MORE INFORMATION section of this article

1. If you replace the MSFlexGrid1_Click() event in the MORE INFORMATION section with the following code, it works as expected:




   Private Sub MSFlexGrid1_Click()

     With MSFlexGrid1

       .Redraw = True
       If .Row = .Rows - 1 Then
         .TopRow = 2
         Debug.Print "Right After Setting .Top Row:  " & .TopRow

       End If

     End With

     Debug.Print "After leaving With block: " & MSFlexGrid1.TopRow

   End Sub 

-or-


2. Using the above workaround will get the MSFlexgrid to move to the correct position. However, doing so may cause the grid to flicker when filling. To avoid this flickering you can use the LockWindowUpdate API call as noted in the below code. Instead of using the above code, replace the code in the MSFlexGrid_Click() event with the following:




   Private Declare Function LockWindowUpdate Lib "user32" _
         (ByVal hwndLock As Long) As Long

   Private Sub fgrItemGrid_Click()

     lres = LockWindowUpdate(Me.hWnd) 'Lock repaints

     With fgrItemGrid

       .Redraw = True
       If .Row = .Rows - 1 Then
         .TopRow = 2
         Debug.Print "Right After Setting .Top Row:  " & .TopRow

       End If

     End With

     lres = LockWindowUpdate(0&) 'Release Lock

     Debug.Print "After leaving With block: " & fgrItemGrid.TopRow

  End Sub 

NOTE: The LockWindowUpdate API can be used to enable or disable a window from repainting. In workaround 2 above, it is used to prevent the window from repainting.

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

1. Start a new Visual Basic 6.0 standard EXE.



2. From the Project menu, choose Components and add a reference to the Microsoft FlexGrid Control 6.0.



3. Add an MSFlexGrid to the default form.



4. Cut and paste the following code into the form:




   Private Sub MSFlexGrid1_Click()

     With MSFlexGrid1

       .Redraw = False
       If .Row = .Rows - 1 Then
         .TopRow = 2
         Debug.Print "Right After Setting .Top Row:  " & .TopRow

       End If
       .Redraw = True
       '.Refresh

     End With

     Debug.Print "After leaving With block: " & MSFlexGrid1.TopRow

   End Sub

   Private Sub Form_Load()
     With MSFlexGrid1
       .RowHeightMin = 288
       .Cols = 10
       .Rows = 5
       .TextMatrix(0, 1) = "Row 0"
       .TextMatrix(1, 1) = "Row 1"
       .TextMatrix(2, 1) = "Row 2"
       .TextMatrix(3, 1) = "Row 3"
       .TextMatrix(4, 1) = "Row 4"
       .Width = 4095
       .Height = 1600
     End With
   End Sub 

5. Click on the "Row 4" cell. The code in the Click event will execute. However, the grid will not refresh and move up so that the TopRow is now 2.
   
   NOTE: Forcing a refresh with the .Refresh method does not correct this problem.

Additional query words:

Keywords : kbCtrl kbVBp600 kbGrpVBDB
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbprb