DOCUMENT:Q186914  08-JUN-1998  [vbwin]
TITLE   :HOWTO: Implement Additional Interfaces in an ActiveX Control
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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SUMMARY
=======

This article demonstrates how to implement an additional interface in a
Visual Basic ActiveX control. ActiveX EXE and DLL components are better
suited for this purpose, but it may be desirable, for example, to implement
a custom interface that is present in all of your ActiveX controls. That is
the approach taken in the example shown in this article.

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

Step by Step Example
--------------------

1. Start a new ActiveX DLL project in Visual Basic. Change the name of the
   project to BaseClass. Change the name of Class1 to CustomInterface.
   Insert the following code into the CustomInterface class module:

      Public Function testCustomInterface()
      End Function

2. On the File menu, click Add Project to add a new ActiveX Control
   project. Click References on the Project menu, and check the reference
   to BaseClass. Insert the following code into the General Declarations
   section of the UserControl's code module:

      Implements BaseClass.CustomInterface

      Private Function CustomInterface_testCustomInterface() As Variant
         CustomInterface_testCustomInterface = _
                               "Custom Interface test successful."
      End Function

      Public Function testStandardInterface() As Variant
         testStandardInterface = "Standard Interface test successful."
      End Function

3. Change the name of the project to interfacesControl. Click Add Project
   on the File menu to add a new Standard EXE project. Right-click on
   Project1 in the Project window and select the Set as Start Up option.

4. On the Project menu, click References, and then check the reference to
   BaseClass. Place the UserControl (interfacesControl) on Form1. Add a
   CommandButton to Form1.

5. Insert the following code into the General Declaration section of
   Form1:

       Private Sub Command1_Click()

          Debug.Print Me.UserControl11.testStandardInterface

          Dim obj As BaseClass.CustomInterface
          Set obj = Me.UserControl11.Object
          Debug.Print obj.testCustomInterface

       End Sub

6. Run the project, click Command1 and note that both interfaces responded
   in the Immediate Window,.

Additional query words: kbDSupport kbDSD kbActiveX kbClientServer kbVBp500
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Version           : WINDOWS:5.0
Platform          : WINDOWS
Issue type        : kbhowto

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