Hi there,

I have built a custom control with its own designer (ControlA). One of the properties for this control is a text string that can hold the ID of another control that implements specific behavior (ControlB).
I created my own TypeConverter that returns an ArrayList with the specific control IDs of type ControlB in the GetStandardValues method. The IDs are retrieved by looping through the controls on the current page (at design-time).

So, when I drag a new instance of my ControlA on the page, the property grid now shows a drop-down list with the IDs of the controls of type ControlB on the page. So far so good.

However, when I add a new instance of ControlB to the page, the drop-down list for ControlA is not updated to show the new ControlB. This makes sense, as ControlA is not aware of this new instance.

Is there a way to catch an event on the main page whenever it has changed? ControlA could subscribe to that event, and update the drop-down with the new instance of ControlB?

I think the validator controls work like that. Whenever I drag a new text box on the page, the ControlToValidate property is updated. Any ideas how I can simulate this behavior??

Thanks in advance,

Imar

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Imar Spaanjaars
http://Imar.Spaanjaars.Com/
===============================================
Everyone is unique, except for me.

This could get squirrely... if it is acceptable for you,you might want to use Roeder's Reflector to see how the validators do it.

The first thing I would try is:
TypeDescriptor.Refresh(typeof(ControlA))


http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemComponentModelTypeDescriptorClassRefreshTopic4.asp

Hi Andrew,

Thanks for your reply. From what location should I call TypeDescriptor.Refresh?

Another option would be to repopulate the drop-down as soon as an instance of ControlA gets the focus / is selected in the page. However, I couldn't find any OnFocus / OnSelect method for the ControlDesigner.....

Currently I am cheating a bit by building the drop-down from ControlB as well. I'll dig into the Validor controls to see how it's done.


Imar

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Imar Spaanjaars
http://Imar.Spaanjaars.Com/
===============================================
Everyone is unique, except for me.

use this typeconverter code from my blog to make your property a control dropdownlist in the designer

Thanks a lot, Andy. This works great.

The trick that solved the problem was context.Container. In my implementation I couldn't get the container object from within the Converter, so I created the ArrayList with control IDs in the designer rather than in the Converter. That way, I always ended up with an out-dated list of controls.

Your code fixes the issue and resulted in a much cleaner implementation.

Thanks again,


Imar

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Imar Spaanjaars
http://Imar.Spaanjaars.Com/
===============================================
Everyone is unique, except for me.