Accessing indexer of base class with identical signature

[Clive Dixon]

Is it possible to access an indexer of a base class with identical
signature, e.g.

class Class1
{
public object this[object o]
{
get
{
// ...
}
}
}

class Class2 : Class1
{
public new object this[object o]
{
get
{
return base.this[o];
}
}
}

The compiler will not accept 'base.this' nor 'base.Item'/'base.get_Item' and
I can't find any reference to calling base class indexers anywhere in the
documentation. Now if the base class indexer has a different signature I can
simply use 'this' rather than 'base.this' and cast the indexer parameter to
that of the base class's indexer to force calling the correct base class
indexer, but if the signatures are identical I cannot see how to call the
base class indexer.

 

[Nicholas Paldino [.NET/C# MVP]]

Clive,

Have you tried using:

return base[o];

Hope this helps.

 

[Larry Lard]

Is it possible to access an indexer of a base class with identical
signature, e.g.

class Class1
{
public object this[object o]

If your method really is called 'this' then I can't even begin to
imagine what the compiler thinks you mean!

class Class2 : Class1
{
public new object this[object o]

Why 'new' when nothing has changed?

 

[Larry Lard]

Larry Lard wrote:
[snip]

class Class2 : Class1
{
public new object this[object o]

Why 'new' when nothing has changed?

Sorry, brainfart, please ignore. My previous comment stands though.

 

[Clive Dixon]

Yep thanks Nicholas. Obvious once pointed out, but I just didn't spot it.

Clive,

Have you tried using:

return base[o];

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

Is it possible to access an indexer of a base class with identical
signature, e.g.

class Class1
{
public object this[object o]
{
get
{
// ...
}
}
}

class Class2 : Class1
{
public new object this[object o]
{
get
{
return base.this[o];
}
}
}

The compiler will not accept 'base.this' nor 'base.Item'/'base.get_Item'
and I can't find any reference to calling base class indexers anywhere in
the documentation. Now if the base class indexer has a different
signature I can simply use 'this' rather than 'base.this' and cast the
indexer parameter to that of the base class's indexer to force calling
the correct base class indexer, but if the signatures are identical I
cannot see how to call the base class indexer.

 

[Michael Bray]

If your method really is called 'this' then I can't even begin to
imagine what the compiler thinks you mean!

It's called an indexer...

Reference: http://msdn.microsoft.com/library/default.asp?url=/library/en-
us/csspec/html/vclrfcsharpspec_10_8.asp

(watch the wrap)

-mdb