FIX: MouseDown Event Fires Unexpectedly on Modal Form

View products that this article applies to.

This article was previously published under Q257543

SYMPTOMS

If the Validate event for a control shows another form modally, then the MouseDown event of the modal form or the control that is under the mouse pointer is fired unexpectedly.

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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 the latest service pack for Visual Studio 6.0.

For additional information about Visual Studio service packs, click the following article numbers to view the articles in the Microsoft Knowledge Base:

194022 (http://support.microsoft.com/kb/194022/EN-US/ ) INFO: Visual Studio 6.0 Service Packs, What, Where, Why

194295 (http://support.microsoft.com/kb/194295/EN-US/ ) HOWTO: Tell That a Visual Studio Service Pack Is Installed

To download the latest Visual Studio service pack, visit the following Microsoft Web site:

http://msdn2.microsoft.com/en-us/vstudio/Aa718353.aspx (http://msdn2.microsoft.com/en-us/vstudio/Aa718353.aspx)

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MORE INFORMATION

Steps to Reproduce Behavior

Start a new Standard EXE project in Visual Basic. Form1 is created by default.
From the Project menu, add an additional Form and a UserControl to the project.
On both Forms, set StartUpPosition = 2 - CenterScreen.
Add a Textbox, a CommandButton, a UserControl to Form1.

Add the following code to the code window of Form1:

Option Explicit

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

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

Private Sub Text1_Validate(Cancel As Boolean)
    Debug.Print "Form1 Text_Validate"
    If Text1.Text = "" Then
        Form2.Show vbModal
    End If
End Sub

Add the following code to the code window of Form2:

Option Explicit

Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
    Debug.Print "Form2 Form_MouseDown"
End Sub

From the View menu, click on Immediate Window to open the immediate window.
Save and run the project.
When you click on Command1 of Form1, you will see in the immediate window, that the MouseDown event of Form2 gets fired after the Validate event of Text1. This is not the expected behavior.