readonly wrapper for a collection

[Ashish]

hi All,
I want to create a readonly wrapper for my strongly typed collection, so
that when i expose it from my containing object as readonly, other
objects are not able to modify it

much like Arraylist.Reado nly but strongly typed..

can i inherit some class in .net or would i have to create two
collection classes of the same return Type ?

comments ?, suggestions ?

regards
-ashish

[Cor Ligthert [MVP]]

Re: readonly wrapper for a collection

Ashish,

Can you rephrase your question and than with less words as 'strongly typed'
, 'wrapper' etc.?

A returned property from an instanced object, which is set in the class of
that readonly, is forever read only (if it is not overloaded).

Cor

[Carlos J. Quintero [VB MVP]]

Re: readonly wrapper for a collection

Create your strongly typed collection inheriting from
System.Collecti ons.ReadOnlyCol lectionBase.

--

Best regards,

Carlos J. Quintero

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"Ashish" <asharma@thisis junk.com> escribió en el mensaje
news:Oe7MEAgzFH A.268@TK2MSFTNG P09.phx.gbl...[color=blue]
> hi All,
> I want to create a readonly wrapper for my strongly typed collection, so
> that when i expose it from my containing object as readonly, other objects
> are not able to modify it
>
> much like Arraylist.Reado nly but strongly typed..
>
> can i inherit some class in .net or would i have to create two collection
> classes of the same return Type ?
>
> comments ?, suggestions ?
>
> regards
> -ashish
>[/color]

[Ashish]

Re: readonly wrapper for a collection

:)

for example i have my Order class that class contains OrderItems
Collection (strongly typed collection of OrderItems).

Orders Class exposes a readonly property called Items, Ideally what i
would like to add/remove order items through Orders.AddItem method and
not through Items.Add method, but i still want the order class to be
able to add items in the orderitems collection.

this can be a little confusing, but please let me know and i cal explain
with some code samples.

regards
-ashish





Cor Ligthert [MVP] wrote:[color=blue]
> Ashish,
>
> Can you rephrase your question and than with less words as 'strongly typed'
> , 'wrapper' etc.?
>
> A returned property from an instanced object, which is set in the class of
> that readonly, is forever read only (if it is not overloaded).
>
> Cor
>
>[/color]

[Cor Ligthert [MVP]]

Re: readonly wrapper for a collection

Ashish,

I have the idea you mean this, I made a simple sample for you.

http://www.windowsformsdatagridhelp.com/default.aspx?ID=b94e5f61-ef37-4b01-a1e1-aabd33779b09

You can try it and tell us if it is what you mean

Cor

[Ashish]

Re: readonly wrapper for a collection

Hi Cor,

thanks for the effort, i saw the code and what i want to do is add items
through order object. in other words do this

myOrder.AddItem (123)

instead of

myOrder.OrderIt ems.add(123)

and ideally i would like to throw exception when a user tries to do
'myOrder.OrderI tems.add(123)', is there any way to expose this
collection as a true readonly ? or would i have to create and maintain 2
collections

regards
-ashish










Cor Ligthert [MVP] wrote:[color=blue]
> Ashish,
>
> I have the idea you mean this, I made a simple sample for you.
>
> http://www.windowsformsdatagridhelp....1-aabd33779b09
>
> You can try it and tell us if it is what you mean
>
> Cor
>
>[/color]

[Cor Ligthert [MVP]]

Re: readonly wrapper for a collection

Ashish,

And how do you want to get those orderitems?

Cor

[Ashish]

Re: readonly wrapper for a collection

well the order class would maintain and expose those orderitems through
the readonly items property

like

Dim myOrder as new Order(1002)

dim myItems as OrderItemCollec tion = myOrder.Items


but when i call

myOrder.Items.A dd(new object)

it should throw error, saying that this collection is readonly



Cor Ligthert [MVP] wrote:[color=blue]
> Ashish,
>
> And how do you want to get those orderitems?
>
> Cor
>
>[/color]