FIX: Incorrect Firing of LostFocus Event (223131)

SYMPTOMS

A Visual Basic 6.0 project contains two forms with Form1 containing a TextBox and a CommandButton. The LostFocus event of the TextBox displays a second form as modal. When you run the project and click the CommandButton, the modal form appears and the CommandButton Click event fires, but should not.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information about Visual Studio service packs, please see the following articles in the Microsoft Knowledge Base:

194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

MORE INFORMATION

Steps to Reproduce Behavior

Start a new Standard EXE project in Visual Basic. Form1 is created by default.
From the Project menu, click Add Form, and then click Open. Form2 is added to your project.
Add a TextBox and a CommandButton to Form1.

Copy the following code to the Code window of Form1:

Option Explicit

Private Sub Command1_Click()
   Debug.Print "Command1_Click"
End Sub

Private Sub Form_Load()
    Text1.Text = ""
    Text1.TabIndex = 0
End Sub

Private Sub Text1_LostFocus()
    Debug.Print "Text1_LostFocus"
    If Text1.Text = "" Then
        Form2.Show vbModal
    End If
End Sub

With the Immediate Window visible, run the project. On the Run menu, select Start, or press the F5 key to start the program. Click the CommandButton.

BUG: The Text1 LostFocus event followed by the CommandButton Click event is fired.

The expected behavior is for the Text1 LostFocus event to fire but the Command1 Click event should not.

REFERENCES

A similar bug behavior is documented in the following article in the Microsoft Knowledge Base:

223101 FIX: WriteProperties Event Executes at Wrong Time

For more information, see the following topics:

Add Form Command (Project Menu) in the Online Help or the MSDN Web site at http://msdn.microsoft.com/library/devprods/vs6/vb/html/vbcmdforminsert.htm (how to add a form to a project).

LostFocus Event in the Online Help or the MSDN Web site at http://msdn.microsoft.com/library/devprods/vs6/vb/html/vbevtlostfocus.htm (explains the LostFocus event).