Q148222: HOWTO: Update Property Values in a Property Page

Article: Q148222
Product(s): Microsoft C Compiler
Version(s): 4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbnokeyword kbActiveX kbCOMt kbCtrl kbMFC kbPropSheet kbVC400 kbVC500 kbVC600 kbGrpDSMF
Last Modified: 10-JUN-2002

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), included with:
   - Microsoft Visual C++, 32-bit Editions, version 4.0 
   - Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
   - Microsoft OLE Control Developer's Kit (CDK) 
   - Microsoft Visual C++.NET (2002) 
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NOTE: Microsoft Visual C++ .NET (2002) supports both the managed code model that is provided by the .NET Framework and the unmanaged native Windows code model. Part or all of the information in this article applies to managed Visual C++ code and may be applied only by using the .NET Framework.

SUMMARY
=======

To modify a property of an OLE control, you would normally change the properties
value in the control's property page. However, it is possible for a property to
be modifiable from more than one property page especially in development
environments such as Visual Basic. In this case, when you change the property in
the control's property page, you should synchronize the value in Visual Basic's
Property Form. This article shows by example how to do it.

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

For example, in Visual Basic, place the Circ3 sample control on the Form page.
Then click the right mouse button to select properties for the control. You will
notice that the same properties can be seen in Visual Basic's Properties window.
For example, one of the properties of Circ3 is the CircleOffset property. If you
change this value in the Control's property page and click Apply, you will
notice that the value has not been updated in Visual Basic's Properties window.
To synchronize the value in both, you need to call BoundPropertyChanged(dispid)
for each property you want to update.

NOTE: The dispid is the id of the property to update. It is usually found in the
header file of the COleControl-derived class. The dispids for the Circ3 control
follow:

     // Dispatch and event IDs
     public:
            enum {
            //{{AFX_DISP_ID(CCirc3Ctrl)
            dispidCircleShape = 2L,
            dispidCircleOffset = 3L,
            dispidFlashColor = 1L,
            dispidNote = 4L,
            eventidClickIn = 1L,
            eventidClickOut = 2L,
            //}}AFX_DISP_ID
            };

The following sample code shows how to modify the Circ3 sample to synchronize the
CircleShape and CircleOffset properties given the dispids above.

Sample Code
-----------

     /* Compile options needed: none
     */ 

     void CCirc3Ctrl::OnCircleShapeChanged()
     {
        SetModifiedFlag();

        // force the control to redraw itself
        InvalidateControl();

        // reset the circle offset, if necessary
        if (m_circleShape)
           SetCircleOffset(0);

        BoundPropertyChanged(dispidCircleShape);      // *ADD THIS LINE*
     }

     void CCirc3Ctrl::SetCircleOffset(short nNewValue)
     {
        // Validate the specified offset value
        if ((m_circleOffset != nNewValue) && m_circleShape&&
            InBounds(nNewValue))
        {
           m_circleOffset = nNewValue;
           SetModifiedFlag();
           BoundPropertyChanged(dispidCircleOffset); // *ADD THIS LINE*
           InvalidateControl();
        }
     }

Additional query words: Property Page Form Browser

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Keywords          : kbnokeyword kbActiveX kbCOMt kbCtrl kbMFC kbPropSheet kbVC400 kbVC500 kbVC600 kbGrpDSMFCATL 
Technology        : kbAudDeveloper kbMFC
Version           : :4.0,5.0,6.0
Issue type        : kbhowto

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