HOWTO: Implement Additional Interfaces in an ActiveX Control

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

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 kbVBp600

Keywords : kbGrpVB
Version :
Platform : WINDOWS
Issue type : kbhowto