[Mono-list] properties with indexers.

Stuart Ballard stuart.ballard@corp.fast.net
Fri, 25 Jul 2003 10:34:20 -0400

Yves Kurz wrote:
> Hallo..
> maybe anyone of you can help me with this. Is it possible to write
> properties which uses indexers? 
> I tried someting like this but i can't compile it:
> class A {
> 	protected object [] o;
> 	public object O [int i] {
> 		get { return o[i]; }
> 		set { o[i] = value; }
> 	}
> }

You want something like this:

class A {
	protected internal object[] o;
	private AO ao = new AO(this);
	public AO O {
		get {return ao;}

class AO {
	private A a;
	internal AO(A a) {this.a = a;}
	public object this[int i] {
		get {return a.o[i];}
		set {a.o[i] = value;}

Basically the trick is to have a readonly property which returns an 
object that supports the indexer. All the other code in the AO class is 
just keeping track of which particular A's O you want to return. Note 
that I made several of the properties internal - this may be necessary 
so that A and AO can talk to each other - as far as I can tell, C# 
supports nested classes like Java, but *doesn't* give those classes 
access to private members.


Stuart Ballard, Senior Web Developer
FASTNET - Web Solutions
(215) 283-2300, ext. 126