Microsoft KB Archive/253211

= PRB: DataGrid and MSHFlexGrid Do Not Scroll Properly Beyond 65,535 Rows =

Article ID: 253211

Article Last Modified on 10/15/2002

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APPLIES TO


 * Microsoft Visual Basic 6.0 Professional Edition
 * Microsoft Visual Basic 6.0 Enterprise Edition

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This article was previously published under Q253211



SYMPTOMS
Using very large recordsets with the Microsoft DataGrid Control 6.0 or the Microsoft Hierarchical FlexGrid Control 6.0 can cause problems when scrolling the grid. When the user drags the thumbtrack to the bottom of the vertical scrollbar, the thumbtrack might jump back to the top. This happens whenever the top row of the grid would have been greater than 65,535.



RESOLUTION
Limit the recordset to fewer than 65,536 records. While the grid can display more rows, you cannot use the thumbtrack to scroll past this number.

This bug does not show up in the OLEDB version of the APEX True DBGrid.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.



Steps to Reproduce Behavior
 Create a new Standard EXE in Microsoft Visual Basic. Form1 is created by default. On the Project menu, select References, and add Microsoft ActiveX Data Objects 2.x Library. On the Project menu, select Components, and add the following:

Microsoft DataGrid Control 6.0 (OLEDB)

Microsoft Hierarchical FlexGrid Control 6.0 SP3 (OLEDB)

 Place two Command buttons, a DataGrid, and a MSHFlexGrid on Form1.  Place the following code into Form1: Option Explicit

Dim rs As ADODB.Recordset

Private Sub Command1_Click Set rs = New ADODB.Recordset With rs     .Fields.Append "Record Number", adBigInt .Open Dim x As Long For x = 1 To 65535 .AddNew ![Record Number] = x        .Update Next x  End With Set DataGrid1.DataSource = rs  Set MSHFlexGrid1.DataSource = rs   Command2.Enabled = True End Sub

Private Sub Command2_Click Dim x As Long With rs     For x = 1 To 5 .AddNew ![Record Number] = .RecordCount .Update Next x  End With Set MSHFlexGrid1.DataSource = rs End Sub

Private Sub Form_Load Command1.Caption = "Add 64K" Command2.Caption = "Add 5" Command2.Enabled = False End Sub  Run the code and click Add 64K. Drag the thumbtrack to the bottom of the vertical scrollbar on each grid, and note that the grids scroll properly.</li> Click the Add 5 Command button until you have enough records to scroll past record number 65,537. Drag the thumbtrack to the bottom of the vertical scrollbar on each grid, and note that the thumbtrack jumps to the top of the recordset when released at the bottom.</li></ol>

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