BUG: Bookmark for Unbound DBGrid is Incorrect for the Last Row

ID: Q176486

The information in this article applies to:

Microsoft Visual Basic Control Creation, Learning, Professional, and Enterprise Editions for Windows, version 5.0

SYMPTOMS

The Bookmark property of the DBGrid control can be used to save a reference to the current row. By setting the Bookmark property, the current row can be updated as well.

If the Bookmark property of an unbound DBGrid control is saved while the last row is selected, setting the Bookmark property back to the saved value will update the current row to be the first row, rather than the last.

RESOLUTION

As a workaround, use the RowBookmark method of the DBGrid control when saving the Bookmark of the current row:


   Private MyBookmark

   Private Sub cmdSaveBookmark_Click()

       MyBookmark = DBGrid1.RowBookmark(DBGrid1.Row)

   End Sub

Also, the following error handling code will need to be included when updating the current row:


   Private Sub cmdRestoreBookmark_Click()
   On Error GoTo err_handler

       DBGrid1.Bookmark = MyBookmark

   Exit Sub

   err_handler:
   Dim r

       If Err.Number = 6149 Then
           For r = 0 To DBGrid1.VisibleRows - 1
               DBGrid1.Row = r
           Next r
           Resume
       Else
           Err.Raise Err.Number
       End If

   End Sub

The above error handling code is necessary because the bug associated with the Bookmark property for the last row will also cause run-time error 6149.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

Open the sample project, UnBndGrd.vbp, in the Visual Basic samples directory (such as C:\Program Files\DevStudio\VB\samples\Misc\UnBndGrd\UnBndGrd.vbp).

This article uses the Sample application UnBndGRd.Vbp. In the current MarchPreRelease of VB 6.0 this sample is not available. This may have to be changed to reflect what is shipped with the product.

Add two CommandButtons to Form1 and name them cmdSaveBookmark and cmdRestoreBookmark.

Add the following code to the General Declarations section of Form1:


      Private MyBookmark

      Private Sub cmdSaveBookmark_Click()

          MyBookmark = DBGrid1.Bookmark

      End Sub

      Private Sub cmdRestoreBookmark_Click()

          DBGrid1.Bookmark = MyBookmark

      End Sub

Run the project.

Select a row in the DBGrid (not the last row) and click on cmdSaveBookmark to save the Bookmark. Move to another row and click on cmdRestoreBookmark to return to the original row.

Repeat step 5 with the last row and notice that the DBGrid does not return to the last row but to the first row instead.

Keywords :
Version :
Platform : WINDOWS
Issue type : kbbug