Hello,
I want to do casting of class A object to class B object.
How exactly can I do it in c#?
The casting I need is: The client will do a casting to a class instance
and I will cast it to another class instance with proper changes.
How to do it?
Thanks!




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"juli jul" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hello,
> I want to do casting of class A object to class B object.
> How exactly can I do it in c#?
> The casting I need is: The client will do a casting to a class instance
> and I will cast it to another class instance with proper changes.
> How to do it?
> Thanks!
>

How are the classes related:

1. the one the client receives
2. the one they cast it to
3. the one you will cast it to

Regards

Richard Blewett - DevelopMentor
http://www.dotnetconsult.co.uk/weblog
http://www.dotnetconsult.co.uk

If I understand you correctly: ((B)oA).<property or method>
But I would use the "as" operator instead and then test for null:

B oB = oA as B;
if (oB != null)
{
<do something with oB>
}

Hope this helps.
--
Thom


"juli jul" wrote:

> Hello,
> I want to do casting of class A object to class B object.
> How exactly can I do it in c#?
> The casting I need is: The client will do a casting to a class instance
> and I will cast it to another class instance with proper changes.
> How to do it?
> Thanks!
>
>
>
>
> *** Sent via Developersdex http://www.developersdex.com ***
>

I forgot to state the obvious, A and B should be related in some way like
derived from the same class or interface or each other.
--
Thom


"tbain" wrote:

> If I understand you correctly: ((B)oA).<property or method>
> But I would use the "as" operator instead and then test for null:
>
> B oB = oA as B;
> if (oB != null)
> {
> <do something with oB>
> }
>
> Hope this helps.
> --
> Thom
>
>
> "juli jul" wrote:
>
> > Hello,
> > I want to do casting of class A object to class B object.
> > How exactly can I do it in c#?
> > The casting I need is: The client will do a casting to a class instance
> > and I will cast it to another class instance with proper changes.
> > How to do it?
> > Thanks!
> >
> >
> >
> >
> > *** Sent via Developersdex http://www.developersdex.com ***
> >

> B oB = oA as B;
> if (oB != null)
> {
> <do something with oB>
> }
>


OR

if (oA is B)
{
(oA as B).Some_B_Method(...);
}




--
hello world

Jeti [work] <(E-Mail Removed)> wrote:
> > B oB = oA as B;
> > if (oB != null)
> > {
> > <do something with oB>
> > }
>
> OR
>
> if (oA is B)
> {
> (oA as B).Some_B_Method(...);
> }

The advantage to the former, of course, is that the cast/check only
gets done once.

--
Jon Skeet - <(E-Mail Removed)>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

> > B oB = oA as B;
> > if (oB != null)
> > {
> > <do something with oB>
> > }

I would prefer

((B oA).<do something>

as it will throw a meaningful exception if oA is not a B, instead of
doing nothing.

Mark Wilden <(E-Mail Removed)> wrote:
> > > B oB = oA as B;
> > > if (oB != null)
> > > {
> > > <do something with oB>
> > > }
>
> I would prefer
>
> ((B oA).<do something>
>
> as it will throw a meaningful exception if oA is not a B, instead of
> doing nothing.

Yes - so would I, very definitely, *if* it really should be that type.
(That's actually the more common case at the moment, I find - generics
may well change that though.)

--
Jon Skeet - <(E-Mail Removed)>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too