Re: IBindingList AllowNew is FALSE!!!

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From: Thomas Tomiczek [MVP] (t.tomiczek_at_thona-consulting.com)
Date: 11/02/04 

Date: Tue, 2 Nov 2004 08:53:46 +0100

It is possible because - and now the fun starts - AddNew is called by the
binding infrastructure if the list is empty to create one intance on which
then reflection can be used to find out sub-instances.

Despite that this information should be available on an ITypedList
interface.

The added objects are then removed afterwards.

Live with it :-) It is pretty hard ,though - whoever made the databinding
architecture should be beaten. 

-- 
Regards
Thomas Tomiczek
THONA Software & Consulting Ltd.
(Microsoft MVP C#/.NET)
(CTO PowerNodes Ltd.)
---
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"Nathan Howard" <NathanHoward@discussions.microsoft.com> wrote in message 
news:8D24803A-62BD-4A67-8809-540B7C0A807D@microsoft.com...
> Hi Anyone,
>
> I am beyond frustrated with the .NET databinding.  I have custom business
> objects and collections for each which implement the IBindingList 
> interface
> and inherit from the CollectionBase.  Several of my business objects 
> contain
> collections of other business objects up to three or four levels deep. 
> For
> the most part they work perfectly but there is one case for which 
> everything
> goes haywire. When my objects are bound to listboxes and the collections 
> are
> empty the CurrencyManager keeps trying to call the AddNew method of the
> IBindingList interface.  I don't see how this is possible considering the
> AllowNew property is set to false on all of my objects.  I don't work in
> datagrids so have no need to implement this portion of the interface.  I 
> need
> help...
>
> Thanks in advance,
> Nathan

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