Q314431: PRB: Programmatically Changing Focus Does Not Cause Validation

Article: Q314431
Product(s): Microsoft Visual Basic for Windows
Version(s): 6.0
Operating System(s): 
Keyword(s): kbActivexEvents kbGrpDSVB kbDSupport
Last Modified: 05-FEB-2002

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The information in this article applies to:

- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
- Microsoft Visual Basic Professional Edition for Windows, version 6.0 
- Microsoft Visual Basic Learning Edition for Windows, version 6.0 
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SYMPTOMS
========

Code that changes the value of a TextBox or of another control, and then moves
the focus to another control where the CausesValidation property is True does
not fire the Validate events of the changed control.

CAUSE
=====

This behavior occurs because changing the focus with code does not trigger
Validate event.

RESOLUTION
==========

To resolve this behavior, call the ValidateControls method when you change
values and focus by the use of code.

STATUS
======

This behavior is by design.

MORE INFORMATION
================

By design, if you change the values of controls in code, you must explicitly
call ValidateControls to run the Validate events. Validate does not run
automatically in this scenario. Similarly, if you close the form after you edit
a control without leaving that control, the Validate event does not fire because
it does not lose focus. In this case, you can use the QueryUnload event of the
Form to decide if ValidateControls should be called.

Steps to Reproduce the Behavior
-------------------------------

1. Open a new Standard EXE project in Visual Basic 6.0; Form1 is created by
  default.

2. Add the CommandButton control, Command1, and two TextBox controls, Text1 and
  Text2, to Form1. CausesValidation is True by default.

3. Add the following code to the General Declarations section of Form1:

  Private Sub Command1_Click()
      Dim i As Integer
      
      For i = 0 To Controls.Count - 1
          If TypeOf Controls(i) Is TextBox Then
             Controls(i).SetFocus
             Controls(i).Text = "Hello! " & i
          End If
      Next i
  End Sub

  Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
      If UnloadMode = vbFormControlMenu Then
  '        Me.ValidateControls
      End If
  End Sub

  Private Sub Command1_GotFocus()
      Debug.Print "Command1 got focus"
  End Sub

  Private Sub Text1_GotFocus()
      Debug.Print "Text1 got focus"
  End Sub

  Private Sub Text1_Validate(Cancel As Boolean)
      Debug.Print "Text1 validate"
  End Sub

  Private Sub Text2_GotFocus()
      Debug.Print "Text2 got focus"
  End Sub

  Private Sub Text2_Validate(Cancel As Boolean)
      Debug.Print "Text2 validate"
  End Sub

4. Press F5 to run the project. Click Command1 and notice the Validate events
  for the TextBox controls do not fire.

5. Edit the contents of Text2 and then close the form. The Validate event is not
  fired for Text2.

6. Uncomment the ValidateControls line in the Form_QueryUnload event, run the
  project, and then repeat step 5; the Validate event fires.

REFERENCES
==========

For additional information about Validate and CausesValidation, click the
article numbers below to view the articles in the Microsoft Knowledge Base:

  Q197128 BUG: CausesValidation Property Does Not Trigger Validate Event

  Q189923 PRB: No Validate Event When Activating CommandButton

Additional query words: Validation

======================================================================
Keywords          : kbActivexEvents kbGrpDSVB kbDSupport 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600
Version           : :6.0
Issue type        : kbprb
Solution Type     : kbnofix

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