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Q189596: SAMPLE: VB6WLCTL.EXE Windowless Controls Demonstration

Article: Q189596
Product(s): Microsoft Visual Basic for Windows
Version(s): 6.0
Operating System(s): 
Keyword(s): kbfile kbole kbreadme kbsample kbCtrl kbRegistry kbVBp kbVBp600 kbOSWin95 kbOSWin98 kbG
Last Modified: 27-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, version 6.0 
- Microsoft Visual Basic Professional Edition for Windows, version 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
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SUMMARY
=======

Visual Basic 6.0 introduces the capability of creating "Windowless" controls. A
Windowless control, also known as a "lightweight" control, is a control that
does not have a WndProc function for message handling. These lightweight
controls require fewer resources than normal controls, and allow for development
of transparent controls. This sample demonstrates how to create windowless
controls in Visual Basic 6.0.

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

The following file is available for download from the Microsoft Download
Center:

  VB6WLCTL.exe
  (http://download.microsoft.com/download/vb60pro/2/2/Win98/EN-US/VB6WLCTL.exe)

Release Date: June 16, 2000

For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:

  Q119591 How to Obtain Microsoft Support Files from Online Services

Microsoft used the most current virus detection software available on the date of
posting to scan this file for viruses. Once posted, the file is housed on secure
servers that prevent any unauthorized changes to the file.

Below is the content of the Readme.txt for this sample.

Description
-----------

Visual Basic 6.0 provides the capability of building Windowless controls, also
known as lightweight controls. A new property of the UserControl, Windowless,
enables this feature. Setting the Windowless property to True will make the
UserControl Windowless, a control which sends and receives messages through OLE
rather than the regular messaging queues that Windows uses.

A Windowless control behaves the same as the normal UserControls with the
following exceptions:

- The UserControl has no hWnd property (limits some API calls).

- The Borderstyle property cannot be set.

- The UserControl cannot host normal Windowed controls.

- Windowless controls are not supported by some containers. If sited in such a
  container, they will be assigned an hWnd and be treated as a normal Windowed
  controls.

This sample demonstrates the functionalities of Windowless controls created in
Visual Basic 6.0. The main project group file is WndLessControlAGroup.vbg, which
contains the controls as well as a client that shows the controls in action. The
documentation in the source code explains in great detail the behavior of each
control.

Summary Of Sample Controls
--------------------------

Four Windowless Controls are included in the sample to show different
Functionality:

TestControl1 - A Windowless control that acts and handles events like a
              normal control.

TestControl2 - Allows events to bypass it and be handled by the controls
              underneath it.

TestControl3 - Demonstrates "HitTesting" to see where the user has clicked
              within the Windowless control's region on the form. The
              control acts "transparently" (events being passed to the
              Form underneath) unless the CommandButton sited on it is
              clicked. Then it handles that Event normally.

TestControl4 - This control demonstrates how to determine what areas of a
              control are transparent by using the Picture, MaskPicture,
              and MaskColor properties, and where events can be handled.

To Start
--------

Before loading this sample into Visual Basic 6.0, the following steps need to be
taken:

1. Copy the following files on the Visual Basic 6.0 or Visual Studio 6.0
  installation CD-ROM in the ...\Common\Tools\VB\WINLESS folder to the
  Windows\System (Windows 95, Windows 98, or Windows Me) or Windows\System32
  (Windows NT) folder:

     mswless.reg
     mswless.ocx

2. Double-click on mswless.reg to import information to the registry.

3. Register mswless.ocx by typing in the following command in the Windows Run
  dialog:

     RegSvr32 C:\Windows\System\mswless.ocx

REFERENCES
==========

For more information about lightweight controls in Visual Basic, please see the
following articles in the Microsoft Knowledge Base:

  Q184687 : INFO: Lightweight Controls in Visual Basic 6.0

  Q184645 : HOWTO: Create Lightweight Controls with Visual Basic 6.0

Additional query words: VB6WLCTL windowless

======================================================================
Keywords          : kbfile kbole kbreadme kbsample kbCtrl kbRegistry kbVBp kbVBp600 kbOSWin95 kbOSWin98 kbGrpDSVB kbDSupport kbOSWinME 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVBA600 kbVB600
Version           : :6.0
Issue type        : kbhowto

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