BUG: Grid Clip Property Contains Remnants of Former Values

• Microsoft Visual Basic Control Creation, Learning, Professional, and Enterprise Editions for Windows, version 5.0
• Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 16-bit and 32-bit, for Windows, version 4.0

SYMPTOMS

Under most circumstances, the Microsoft Grid control's Clip property will contain only the values of all the currently-selected cells in the grid. However, in Visual Basic 4.0 16-bit, if a cell in a selected range contains a null value, previously selected values will show through in the Clip property at the position of the cell containing a null value. In Visual Basic 4.0 16- and 32-bit, if the last cell in a selected range contains a null value then all previously selected cell values at that position and beyond will be added to the Clip property.

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

This behavior does not occur with the newer MSFlexGrid that ships with Microsoft Visual Basic version 5.0.

Steps to Reproduce Behavior

1. Start a new project in Visual Basic 4.0.

2. Choose Custom Controls from the Tools menu. Select " Grid Control."

3. Add one CommandButton (Command1).

4. Add one grid control (Grid1), large enough to show a 5 x 5 grid.

5. Add the following code to Form1:

         Option Explicit
   

         Private Sub Command1_Click()
            Dim x as Integer, y as Integer
            ' Create a 5 by 5 grid.
            Grid1.Cols = 5
            Grid1.Rows = 5
            ' Fill the grid with some sample values.
            For x = 1 To 4
               Grid1.Col = x
               For y = 1 To 4
                  Grid1.Row = y
                  Grid1.Text = x + y
               Next y
            Next x
            ' Select a range of cells.
            Grid1.SelStartCol = 1
            Grid1.SelStartRow = 1
            Grid1.SelEndCol = 4
            Grid1.SelEndRow = 1
            ' Show the clip property contents.
            MsgBox "The contents of the clip property: " & Grid1.Clip
            ' Select a new range of cells.
            Grid1.SelStartCol = 2
            Grid1.SelStartRow = 3
            Grid1.SelEndCol = 3
            Grid1.SelEndRow = 3
            ' Set current cell to the last cell in the selected range.
            Grid1.Col = 3
            Grid1.Row = 3
            MsgBox "Now clearing last selected cell."
            ' Set the cell to a null value.
            Grid1.Text = ""
            ' Show the new contents of the clip property.
            MsgBox "NOW Notice the contents of the clip property" & _
              Chr(13) & Chr(10) & "compared to the selected cells: " & _
              Grid1.Clip
         End Sub
   
   

6. Press the F5 key to run the project.

REFERENCES

For additional information, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q150229
   TITLE     : BUG: Setting Grid Clip Property to Empty Text Box Causes GPF