DOCUMENT:Q189608  17-JUL-1998  [vbwin]
TITLE   :BUG: TreeView ToolTips Flash When Displayed From Modal Form
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:5.0
OPER/SYS:WINDOWS
KEYWORDS:

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The information in this article applies to:

 - Microsoft Visual Basic Learning, Professional, and Enterprise Editions
   for Windows, version 5.0
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SYMPTOMS
========

When the Microsoft TreeView control has been added to a Visual Basic form,
and the user hovers the mouse cursor over a node whose text is longer than
the control's width, a ToolTip should appear with that text. However, if
the form is being displayed modally, the ToolTips will "flash" on and off
repeatedly. This behavior occurs only in the compiled version of the
application and not in the Visual Basic design environment (IDE.)

Currently, this problem is limited to the Windows 95 and Windows 98
platforms.

RESOLUTION
==========

Whenever possible, limit the use of the TreeView control to non-modal
forms. If you need to use the TreeView control in a modal dialog, you can
simulate modal behavior using a method such as the one documented below.

NOTE: The following method uses a Do-While loop with a single DoEvents
statement to force the program to continually poll and process messages
from the message queue while it waits for the dialog to be hidden. While
this technique will work in most cases, it is highly inefficient and has
been known to cause some problems with control event notification.

NOTE: Microsoft provides this workaround for illustration only, without
warranty either expressed or implied, including, but not limited to, the
implied warranties of merchantability and/or fitness for a particular
purpose.

To simulate invoking a Visual Basic Form modally, use the following call in
place of the normal Show method:

   ShowModalForm Form2

The code for ShowModalForm is shown below, and can be placed in a Form or
standard code module:

   Public Sub ShowModalForm(frmTarget As Form)
      Dim ofrm As Object

      ' Disable all the forms
      For Each ofrm In Forms
        ofrm.Enabled = False
      Next ofrm

      ' Now show the target form non-modal
      frmTarget.Show

      ' If the frmTarget was disabled by the loop above
      ' make sure it is now enabled
      frmTarget.Enabled = True

      ' Sit in a loop until the target form is dismissed
      Do While frmTarget.Visible = True
         DoEvents
      Loop

      ' We have left the loop, so the dialog has been dismissed
      ' Now Enable the forms, and exit the procedure
      For Each ofrm In Forms
         If ofrm.Name = frmTarget.Name Then
            Unload ofrm
         Else
            ofrm.Enabled = True
         End If
      Next ofrm
   End Sub

STATUS
======

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

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

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

1. Create a new Standard EXE project. Form1 is created by default.

2. From the Project menu, click Components, and check "Microsoft Windows
   Common Controls."

3. Add a CommandButton to Form1.

4. Paste the following code into Form1's code window:

      Private Sub Command1_Click()
         Form2.Show vbModal
      End Sub

5. From the Project menu, click Add Form and add a new form, Form2, to
   the project.

6. Place a TreeView control on Form2. Size it to be about 1/2 inch wide.

7. Paste the following code into Form2's code window:

      Private Sub Form_Load()
         With TreeView1
            .Nodes.Add Key:="TEST1", _
               Text:="Test1 : Does Long Node Text Name Flash?"
            .Nodes.Add Key:="TEST2", _
               Text:="Test2 : Does Long Node Text Name Flash?"
            .Nodes.Add Key:="TEST3", _
               Text:="Test3 : Does Long Node Text Name Flash?"
         End With
      End Sub

8. Choose Make exe from the File menu to compile the project to an EXE.

9. Run the compiled program and click on Command1. Note that as you hover
   the mouse over the nodes of the TreeView, the ToolTip that appears will
   flash.

REFERENCES
==========

For additional information, please see the following article in the
Microsoft Knowledge Base:

   ARTICLE-ID: Q173943
   TITLE     : BUG: TreeView ToolTips Do Not Appear on Windows NT

Additional query words: kbDSupport kbDSD kbVBp kbCtrl kbVBp500bug kbWinOS98
kbWinOS95
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Version           : WINDOWS:5.0
Platform          : WINDOWS
Issue type        : kbbug
Solution Type     : kbpending

=============================================================================

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