Then why is the interface public?

Thanks,

Shawn Wildermuth
Wildermuth Consulting Services, LLC
http://adoguy.com
C# MVP, MCSD.NET, Author and Speaker


> -----Original Message-----
> From: Discussion of advanced .NET topics.
> [mailto:[EMAIL PROTECTED] On Behalf Of Mike Andrews
> Sent: Friday, July 07, 2006 4:22 PM
> To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM
> Subject: Re: [ADVANCED-DOTNET] Implementing an Interface - C#
> vs. VB.NET
>
> The answer is that I want these methods to be utilized only
> within the context of the namespace they are in.  I don't
> want them accessible outside, but only used as internal
> features of the object.
>
> Thanks,
> Mike
>
> On 7/7/06, Shawn Wildermuth <[EMAIL PROTECTED]> wrote:
> >
> > Then I would:
> >
> > public abstract class T: IBusiness {
> >
> > public virtual void Remove() {
> >    throw new Exception("The method or operation is not
> implemented.");
> > }
> >
> > public virtual void Save() {
> >      throw new Exception("The method or operation is not
> > implemented."); }
> >
> > public virtual Guid ID {
> >    get {
> >      throw new Exception("The method or operation is not
> implemented.");
> >    }
> >    set {
> >      throw new Exception("The method or operation is not
> implemented.");
> >    }
> > }
> > }
> >
> > I am not sure based on your explanation so far, why you
> need to hide
> > the methods/properties with protected/internal in the base
> class?  Its
> > abstract so you can't create an instance of it anyway.
> >
> > A derived class could:
> >
> > public class X : T
> > {
> > public override void Remove()
> > {
> >    // call base implemenation
> >    base:Remove();
> >
> >    // do more stuff
> > }
> > }
> >
> > If you want to get fancy and unnecessary you could also:
> >
> > public abstract class T: IBusiness {
> >
> > public virtual void Remove() {
> >    innerRemove();
> > }
> >
> > // ... rest of interface
> >
> > protected internal void innerRemove()
> > {
> >    // do remove work here
> > }
> >
> > // ... rest of interface
> > }
> >
> > But that seems silly to me...
> >
> > HTH
> >
> > Thanks,
> >
> > Shawn Wildermuth
> > Wildermuth Consulting Services, LLC
> > http://adoguy.com
> > C# MVP, MCSD.NET, Author and Speaker
> >
> >
> > > -----Original Message-----
> > > From: Discussion of advanced .NET topics.
> > > [mailto:[EMAIL PROTECTED] On Behalf Of Mike
> > > Andrews
> > > Sent: Friday, July 07, 2006 4:06 PM
> > > To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM
> > > Subject: Re: [ADVANCED-DOTNET] Implementing an Interface - C# vs.
> > > VB.NET
> > >
> > > Thank you.
> > >
> > > However, that does not help with the idea that a base class
> > > implements an interface and then I re-implement the interface on
> > > derived classes where needed.  This is so that ever class that
> > > inherits from the base class also implements the
> interface, even if
> > > I do not re-implement it for the derived class.  But some derived
> > > classes will add their own functionality.
> > >
> > > Thanks,
> > > Mike
> > >
> > >
> > > On 7/7/06, gregory young <[EMAIL PROTECTED]> wrote:
> > > >
> > > > You have to do whats called "explicitly implementing" a
> > > interface. See
> > > > http://msdn2.microsoft.com/en-us/library/4taxa8t2.aspx
> > > >
> > > > Cheers,
> > > >
> > > > Greg
> > > >
> > > >
> > > > On 7/7/06, Mike Andrews <[EMAIL PROTECTED]> wrote:
> > > > >
> > > > > Guys,
> > > > >
> > > > > I have a question that I need some help with in regards to
> > > > > implementing
> > > > an
> > > > > interface.
> > > > > I've been a VB programmer for most of my career and now I
> > > use C#.
> > > > > Some
> > > > of
> > > > > the functionality that I used in VB seems to be lacking in C#.
> > > > > I wanted to know if it's my imagination or if there's a
> > > workaround.
> > > > >
> > > > > The base problem is that I want to change the access level on
> > > > > interface methods once they are implemented in a class.
> > > However, C#
> > > > > seems to cry and such changes and VB seems to allow them.
> > > > > Here's the example:
> > > > >
> > > > > Here's the VB example:
> > > > >
> > > > > Public Interface IBusiness
> > > > >
> > > > >    Sub Remove()
> > > > >    Sub Save()
> > > > >    Property ID() As Guid
> > > > >
> > > > > End Interface
> > > > >
> > > > > Public MustInherit Class T
> > > > >    Implements IBusiness
> > > > >
> > > > >    Public MustOverride Sub DoStuff()
> > > > >
> > > > >    Protected Friend Overridable Property ID() As System.Guid
> > > > > Implements IBusiness.ID
> > > > >        Get
> > > > >
> > > > >        End Get
> > > > >        Set(ByVal value As System.Guid)
> > > > >
> > > > >        End Set
> > > > >    End Property
> > > > >
> > > > >    Protected Friend Overridable Sub Remove() Implements
> > > > > IBusiness.Remove
> > > > >
> > > > >    End Sub
> > > > >
> > > > >    Protected Friend Overridable Sub Save() Implements
> > > IBusiness.Save
> > > > >
> > > > >    End Sub
> > > > >
> > > > > End Class
> > > > >
> > > > > Notice in this example that these methods are the
> > > implementation for
> > > > > IBusiness, but I changed the access modifiers to Protected
> > > > > Friend
> > > > instead
> > > > > of
> > > > > public or something else.
> > > > >
> > > > > Now, in C#, if I try to do the same, I get a compiler error:
> > > > >
> > > > >    public interface IBusiness {
> > > > >
> > > > >        void Remove();
> > > > >        void Save();
> > > > >        Guid ID { get; set;}
> > > > >
> > > > >    }
> > > > >
> > > > >    public abstract class T: IBusiness {
> > > > >
> > > > >
> > > > >        #region IBusiness Members
> > > > >
> > > > >        public void Remove() {
> > > > >            throw new Exception("The method or
> operation is not
> > > > > implemented.");
> > > > >        }
> > > > >
> > > > >        public void Save() {
> > > > >            throw new Exception("The method or
> operation is not
> > > > > implemented.");
> > > > >        }
> > > > >
> > > > >        public Guid ID {
> > > > >            get {
> > > > >                throw new Exception("The method or
> > > operation is not
> > > > > implemented.");
> > > > >            }
> > > > >            set {
> > > > >                throw new Exception("The method or
> > > operation is not
> > > > > implemented.");
> > > > >            }
> > > > >        }
> > > > >
> > > > >        #endregion
> > > > >
> > > > >    }
> > > > >
> > > > > If I change the public members to protected or
> private I get an
> > > > error.  If
> > > > > I
> > > > > change them to explicit implementation, then I cannot access
> > > > > them regardless unless I cast to the interface.
> > > > >
> > > > > What I'm want to do is implement an interface in a base class
> > > > > (so that I don't have to implement it in every derived class)
> > > > > and then
> > > > "re-implement"
> > > > > for the derived class where necessary but have a
> > > protected internal
> > > > access
> > > > > modifier.
> > > > >
> > > > > Any suggestions or am I barking up the wrong tree here?
> > > > >
> > > > > Thanks,
> > > > > Mike
> > > > >
> > > > > ===================================
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> > > >
> > > >
> > > >
> > > > --
> > > > If knowledge can create problems, it is not through
> > > ignorance that we
> > > > can solve them.
> > > >
> > > > Isaac Asimov
> > > >
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