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Q190512: HOWTO: Read Extender Properties from a UserControl

Article: Q190512
Product(s): Microsoft Visual Basic for Windows
Version(s): 
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, versions 5.0, 6.0 
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
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SUMMARY
=======

There are times when your UserControl needs to check the value of an Extender
Property when your control loads. This example shows how to check the values of
Extender Properties from inside the UserControl. As an author of a control, you
should not attempt to set Extender Properties with code in the UserControl.

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

Extender properties are provided by the container your control is placed on, but
they appear to be a seamless extension of your control. A UserControl object can
access extender properties through its Extender object.

To access an extender property, you must make sure your control is sited on the
container. When the ReadProperties event of a UserControl happens, the control
should be sited. However it still may not have access to all the extender
properties. Because of this, the best place to read the value of an extender
property is from the controls Show event.

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

1. Create a new ActiveX Control project. UserControl1 is created by default.

2. Change the BackColor of the UserControl to a different color such as red.

3. Add the following code to the UserControl:

        Private Sub UserControl_Show()
           Debug.Print "WhatsThisHelpID " & Extender.WhatsThisHelpID

           Debug.Print "Tooltiptext " & Extender.ToolTipText
           Debug.Print "HelpContextID " & Extender.HelpContextID
           Debug.Print "Tag " & Extender.Tag
           Debug.Print "Name " & Extender.Name
        End Sub

4. Close the UserControl's design and code windows.

5. From the File Menu, select Add Project, and add a Standard EXE project. Form1
  is created by default.

6. Make the Standard EXE project the Startup project by choosing Properties from
  the Project menu and, on the General tab, pick Form1 as the Startup Object.

7. Place an instance of the UserControl on Form1. You will see a list of
  Extender properties in the Immediate Window.

8. Set the following properties for UserControl1 on Form1:

        WhatsThisHelpID = 101
        HelpContextID= 101
        Tag = "MyControl"
        ToolTipText = "Usercontrol"
        Name = "Bubba"

9. Save and run the project group. In the Immediate window you will see the new
  values for the different Extender properties.

REFERENCES
==========

For more information, Search for Extender Object in Online Help and read
"Understanding the Container's Extender Object" in the "Component Tools Guide."

Additional query words: kbDSupport kbDSD kbVBp kbVBp500 kbVBp600 kbCtrlCreate

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Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600
Issue type        : kbhowto

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