c# - How to make a List of Generic Objects? -

i'm having trouble situation:

i've generic class:

public class informationsolv<t> {     private t _valeur;      public string nom { get; private set; }     public datetime timestamp { get; set; }      ... } 

i store objects of informationsolv type in collection.

so store in list of objects have cast every time want information object.

so thought "i should make abstract class , make informationsolv inherit it"

so did:

public abstract class ainformationsolv {     public string nom;     public datetime timestamp; } 

and changed informationsolv this:

public class informationsolv<t>:ainformationsolv {     private readonly t _valeur;      ... } 

it's not bad, if make list of ainformationsolv objects , store informationsolv objects in it. can access nom , timestamp variables (without cast) of course can't access _valeur neither can put _valeur in ainformationsolv class, because have become generic class , problem same.

is there way can make in abstract class:

public abstract class ainformationsolv {     public string nom;     public datetime timestamp;     protected ? _valeur; } 

where ? means: "child classes contain _valeur class variable, don't know type variable, child define it".

thank you

is there way can define member type mans "children classes contain _valeur class variable, don't know type variable, children define it".

sure - use object type:

protected object _valeur; 

think - if _valeur can of different types - how know type you're dealing @ compile time? , how use it?

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take list<t> example - suppose want list<list<?>>, inner list can of type. right can use list<object>, can use list<ienumerable<object>> guarantee inner lists @ least form of ienumerable<t>. let's suppose syntax existed:

var funkylist = new list<list<?>>(); 

i can add lists of type:

funkylist.add(new list<int>()); funkylist.add(new list<foo>()); funkylist.add(new list<bar>()); 

now extract 1 of inner lists:

list<?> l = funkylist[1]; 

but ?? if don't know type of list is, how going useful it? @ best you'd have use reflection (or dynamic) inner type anyways, negates power of generics.