vb.net - How should I store Child Classes in an enumerable and how to access them correctly? -

vb.net - How should I store Child Classes in an enumerable and how to access them correctly? -

public class uniquelist(of t baseclass) inherits list(of t) public overridable overloads sub add(value t) if not me.contains(value) mybase.add(value) end sub public function [get](val integer) t homecoming me.where(function(cb) cb.id = val)(0) end function end class

i en error if seek utilize without casting first, i cast before trying object :

dim mylist new uniquelist(of baseclass) mylist.add(new childclass(1)) dim x childclass= (mylist.get(1)) x.randommethod() ...

so tried create new function in uniquelist class cast me :

public function [getchildclass](val integer) childclass homecoming directcast(me.where(function(cb) cb.id = val)(0), childclass) end function

but errors saying value t cannot converted childclass... there way have function returns me right object ?

edit: cant alter list of childclass ...

edit : declare them want ...

class baseclass public id integer public sub new(id integer) me.id = id end sub end class class childclass inherits baseclass public sub new(id integer) mybase.new(id) end sub public sub randommethod() 'do nil end sub end class

you may looking this:

public function [getparent](val integer) childclass homecoming directcast(me.oftype(of childclass). where(function(cb) cb.id = val)(0), childclass) end function

note - fail if no elements of type childclass found, can prevent failing using .firstordefault instead of manually indexing (0) first element. firstordefault homecoming nothing if no elements found.

vb.net