Q149326: FIX: Multiselect with ListView Causes Lost Mouse Events

Article: Q149326
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0
Operating System(s): 
Keyword(s): kbVBp500 kbGrpDSVB
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Control Creation Edition for Windows, version 5.0 
- Microsoft Visual Basic Learning Edition for Windows, version 5.0 
- Microsoft Visual Basic Professional Edition for Windows, version 5.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 5.0 
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SYMPTOMS
========

When the MultiSelect property of the ListView control is set to True, neither
the MouseUp or Click event is generated when the ListView control itself is
clicked. The only event generated in this case is the MouseDown event. This
problem occurs only if the area clicked on does not contain a ListItem object.
If a ListItem is clicked, all three events are fired as expected.

RESOLUTION
==========

The fired MouseDown event can be used instead of the Click event to execute code
when a user clicks the white space of a ListView control. If it is vital that
some action be taken when the mouse button is released, one can manually trap
the WM_LBUTTONUP message sent to the control using a message trapping OCX or
tool. The Message Blaster OCX produced by WareWithAll is a good example of a
control that provides this functionality.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug has been fixed in Visual Basic 6.0.

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

Steps to Reproduce
------------------

1. Start Visual Basic 4.0. Form1 is created by default.

2. Add a single ListView control to the form.

3. Set this property of the ListView control:

  MultiSelect: True

4. Add this code to Form1:

     Private Sub Form_Load()
         Dim lv As ListItem
         Dim i As Integer

         For i = 1 To 10
             Set lv = ListView1.ListItems.Add(, , "Item " & i)
         Next i
     End Sub

     Private Sub ListView1_Click()
         Debug.Print "ListView1_Click"
     End Sub

     Private Sub ListView1_MouseDown(Button As Integer, Shift As Integer, _
       x As Single, y As Single)
         Debug.Print "ListView1_MouseDown"
     End Sub

     Private Sub ListView1_MouseUp(Button As Integer, Shift As Integer, _
     x As Single, y As Single)
         Debug.Print "ListView1_MouseUp"
     End Sub

5. Press F5 or select Start from the Run menu to run the application. Click on a
  portion of the ListView control that does not contain a ListItem object. Note
  that only the MouseDown event is fired.

Additional query words: kbVBp400bug kbVBp500fix kbVBp600fix kbVBp kbdsd kbDSupport kbControl

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Keywords          : kbVBp500 kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVBA500Search kbVBA500 kbVB500 kbVB400Search kbVB400 kbZNotKeyword3
Version           : :4.0,5.0
Issue type        : kbbug
Solution Type     : kbfix

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