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How to be notified when a inherited property is changed?

Posted on 1997-08-17
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Last Modified: 2010-04-03
I am writing a component which displays a different picture when disabled. How do I know that the enabled property is changed? I can do this by writing "Property Enabled:Boolean read FEnabled write SetEnabled" and do the things I want in the SetEnabled procedure if Enabled is a property declared by me. But this Enabled property is inherited from TCustomControl. I cannot do this in a inherited property. How to tell Delphi to do my code then do the inherited code when the Enabled property is changed?
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Question by:sccheung
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by:sccheung
ID: 1341643
Why don't you answer my question? Not enough points? I increase points to 20. Please answer my question!
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icampbe1 earned 20 total points
ID: 1341644
Descend from TCustomControl (or whatever you are using), and declare an Enabled property of your own.  This will 'hide' (not override) the ancestor Enabled.  Create an event like OnEnabledChange in your descendant control.  When the Enabled property is changed, call the Inherited Enabled with that new value and then trigger your own OnEnabledChange event.  That's how you would do it.

I'm assuming you don't want an example for 20 points.

Hope this helps,
Ian C.
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