PRB: When Event Fires Again Upon Leaving a Grid Column

ID: Q148408

3.00 3.00b WINDOWS kbtool kbprb

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b

SYMPTOMS

If there is only one column enabled in a grid and you try to use SetFocus to move the focus programmatically to another object such as a command button, the focus moves to the command button correctly but the grid also moves the active grid cell to highlight the next available cell. Because there is only one active column, there is no "next available cell," so the cell that's activated ends up being the same that fired the When event, so the When event of that column fires again.

RESOLUTION

There are a number of workarounds for this situation:

Add a small dummy column to the grid so that the focus can move off the original cell that implemented the When event onto the dummy column.
-or-
Set the SelectedOnEntry property to False so that the effect is less noticeable.
-or-
If the problem is that the When event fires when you manually try to move to another object in the VALID, check for movement key presses such as TAB or ENTER in the KeyPress method of the column, and substitute with CTRL+TAB, which will prevent the attempt to move the pointer to the next column.

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a new form. Place a grid (Grid1) and a command button (Command1)

   on the form.

2. Set the following properties of the Grid:

   ColumnCount=3
   Column1.Enabled=.F.
   Column2.Enabled=.T.
   Column3.Enabled=.F.

3. Place the following code in the When event for Grid1.Column2.Text1:

   WAIT WINDOW 'In WHEN for Col2' NOWAIT

4. Add the following code to the Valid method Grid1.Column2.Text1:

   THISFORM.Command1.SetFocus

5. Run the form, and press TAB from within the grid. The focus moves to

   Command1, but the When event of the grid still fires.

6. To remedy the problem, add the following code to the KeyPress method for

   Grid1.Column2.Text1:

   IF nKeyCode=9 OR nKeyCode=13
     NODEFAULT
     KEYBOARD '{CTRL+TAB}'
   ENDIF

Additional reference words: 3.00 3.00b VFoxWin KBCategory: kbtool kbprb KBSubcategory: FxtoolFormdes

Keywords          : FxtoolFormdes 
Version           : 3.00 3.00b
Platform          : WINDOWS