PRB: MouseMove Events Fires on Disabled Control in VFP

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a

SYMPTOMS

In Visual FoxPro 3.x and 5.x, the MouseMove event fires when you move over a disabled control. This behavior may confuse some developers because the MouseMove event does not fire on a disabled control in Visual Basic 5.0 and Microsoft Access 97.

RESOLUTION

You must write code to determine the status of the Enabled property of the object and then conditionally perform the MouseMove event method code. The following code checks if the object's Enabled property is true and if so, permits your MouseMove method code to conditionally execute.

   IF This.Enabled=.t.
      ThisForm.Command2.Visible=.f.
   ENDIF

STATUS

This behavior is by design.

MORE INFORMATION

This is the desired behavior in Visual FoxPro. Since Visual FoxPro does not automatically disable the MouseMove event of a disabled object, it offers you more flexibility in application design. If you want to emulate the behavior found in Visual Basic or Microsoft Access 97, see the RESOLUTION section above.

Steps to Reproduce Behavior

1. Create a form that contains two command buttons.

2. In Command1, set the Enabled property to false (.F.) and add the following code to the MouseMove event:

         Thisform.Command2.Visible=.F.
   

3. Run the form and move the icon over the disabled command button. The MouseMove fires and the Command2 object becomes invisible.