BUG: Data Control Validate Event Not Fired on Unloading Form

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 16-bit and 32-bit, for Windows, version 4.0

SYMPTOMS

A form containing a bound Data Control disables the Validate event when the form is unloaded.

STATUS

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

MORE INFORMATION

The following are steps to reproduce this behavior. The Cancel property is set to true in the Unload event of the form to prevent the form from unloading. When you edit a record and then unload the form, the validate event, containing a beep instruction, executes only one more time.

Steps to Reproduce Behavior

1. Start 16-bit or 32-bit Visual Basic 4.0, or if it is already running, click New Project on the File menu.

2. Add the following controls and set the following properties:

         Control              Default Name   Property              Value
         --------------------------------------------------------------------
   
         Data Control            Data1       Database Name         BIBLIO.MDB
                                             RecordSource          Authors
   
         TextBox Control         Text1       DataSource            Data1
                                             DataField             Author
   
         Command Button          Command1
   
   

3. Copy the following code to the Code window of the Form1 form:

         Option Explicit
   

         Private Sub Command1_Click()
            Unload Me
         End Sub
   
         Private Sub Data1_Validate(Action As Integer, Save As Integer)
            Beep
         End Sub
   
         Private Sub Form_Unload(Cancel As Integer)
            'The next line stops the form from being unloaded
            Cancel = True
         End Sub
   
   

4. On the Run menu, click Start or press the F5 key to start the program. Scroll through the records and click the command button. Note that a beep occurs with each action.

5. Edit a record and click the command button. Scroll through the records and note the a beep occurs only once. Scrolling through the records or clicking the command button does not execute the Validate event.