Q189483: BUG: Cannot Set RichTextBox Visible Property to False

Article: Q189483
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:5.0
Operating System(s): 
Keyword(s): kbGrpDSVB
Last Modified: 11-JAN-2001

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The information in this article applies to:

- 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 
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SYMPTOMS
========

Setting the Visible property of a Rich TextBox control to False does not hide
the control after using the Span method of that control.

RESOLUTION
==========

To work around this problem, add a call to the ShowWindow API function, passing
the SW_HIDE constant after setting the Visible property of the Rich Textbox to
False. This can be tested by uncommenting the following line in the sample code
in the MORE INFORMATION section below:

     result = ShowWindow(RichTextBox1.hwnd, SW_HIDE)

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. Start a new Standard EXE project. Form1 is created by default.

2. From the Project menu, click Components, and check the "Microsoft Rich
  Textbox Control."

3. Place a Rich Textbox Control along with three CommandButtons onto Form1, and
  add the following code to the form's module:

        Private Declare Function ShowWindow Lib "user32" _
        (ByVal hwnd As Long, ByVal nCmdShow As Long) As Long

        Const SW_HIDE = 0

        Private Sub Form_Load()
           Command1.Caption = "Span and Hide"
           Command2.Caption = "Hide"
           Command3.Caption = "Show"
        End Sub

        Private Sub Command1_Click()
           Dim result As Long

           Debug.Print "Before Span: Visible = " & RichTextBox1.Visible
           RichTextBox1.Span ".?!:", True, True  ' Select to the end
           Debug.Print "After Span: Visible = " & RichTextBox1.Visible
           RichTextBox1.Visible = False
           '************
           ' Uncomment the following line to hide the Rich TextBox
           ' result = ShowWindow(RichTextBox1.hwnd, SW_HIDE)
           '************
           Debug.Print "After set Visible to False: Visible = " & _
              RichTextBox1.Visible
        End Sub

        Private Sub Command2_Click()
           RichTextBox1.Visible = False
        End Sub

        Private Sub Command3_Click()
           RichTextBox1.Visible = True
        End Sub

4. Run the project and click "Span and Hide" twice. Notice that the Rich TextBox
  is visible despite the fact it's Visible property is explicitly set to False.

5. Remove the comment from the ShowWindow call and run the sample again. Notice
  that the problem no longer occurs.

REFERENCES
==========

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

  Q149463 RichTextBox Appears Even If Visible Property is False

Additional query words: kbDSupport kbDSD kbVBp kbCtrl kbvbp400bug kbVBp500bug

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Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVBA500 kbVB500
Version           : WINDOWS:5.0
Issue type        : kbbug
Solution Type     : kbnofix

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