How: To get true dynamic polymorphism (i.e. smalltalk)

[Yechezkal Gutfreund]

I have two subclasses of SpriteModel (1) LocalSprite (2)Sprite

Both implement a method called .ToXml() which returns an XmlDocument. But
they are different.

I instances of these objects stored in a Hashtable. Extracting them from the
Hashtable means that I get a object that is tentatively an instance of Class
Object (or Type Object to use the correct C# word).

I can HARD cast the object to a SpriteModel, and then invoke the .ToXml()
method, but if either of these sublcasses overrides or NEWs the default
method in SpriteModel. I can't get to it.

What I want to do is dynamically cast the object extracting from the
Hashtable to it's .GetType

realType = spriteList.Valu e.GetType()

and then do something like a dynamic cast (realType)sprit eList.Value

Obviously, this is very wrong syntacically, but there most be something that
is kosher that does the same effect? right? I don't have to resort to
Reflection and P/Invoke do I?

public override string ToString()
{
StringBuilder response = new StringBuilder() ;
lock (this.spriteTab le) {
IDictionaryEnum erator spriteList = this.spriteTabl e.GetEnumerator ();
while (spriteList.Mov eNext())
{
SpriteModel sprite = (SpriteModel)sp riteList.Value;
response.Append (Tools.PrettyPr int(sprite.ToXm l().DocumentEle ment));
response.Append ("\r\n");
}
}
return response.ToStri ng();
}

[junk]

[This followup was posted to microsoft.publi c.dotnet.framew ork and a
copy was sent to the cited author.]

In article <OC************ **@TK2MSFTNGP11 .phx.gbl>,
sg********@hotm ail.com says...

To put this in TCL/TK or Smalltalk way of speaking I am looking for the
equivelent of

(random object).perform Method("named method")

I.e. I want to invoke methods dynamically at run-time

Assume I already did the checking that this method is implemented by the
object, so that I don't get a run-time error

[Yes, I am not a fan of 100% rigidly hard-typed systems, since there are
times where one needs to get around this]

In my opinion Frank Oquendo's response is in the correct track.