Create a generic list List where T is only known at runtime

Question

Please help,
I have a method that returns an Object. This returned object could be a generic list of 4 or more classes in my code.
i.e the object could be List<class1>, List<class2>, List<class3> etc.
At runtime when I recieve this object, I want to be able to cast it to a list of the appropriate type.
PS. The methods return value is object. The writers of this class that I'm calling basically create a generic list and fill it up, then for reason i cant explain, they cast the list to an object and return is.
The return line is exactly ==> return (object)thegeneicList
How do I go about creating a generic list List<T> where T is only known at runtime

LB Elbino · Answer

Thanks Allan

Alan · Answer

The method would only be able to have a return type of List if T were a type parameter of the method itself or of the class/struct of which the method were a member. Otherwise, the only return type that can be used is 'object' because all generic List classes inherit directly from it. Moreover, two closed contructed generic classes, List and List , have no conversion relationship with each other even if A and B themselves do. This also means that the only way you can cast the object to a List of the appropriate type is to consider each case individually. For example: List list1 = null; List list2 = null; List list3 = null; List list4 = null; if (obj is List ) list1 = (List )obj; else if (obj is List ) list2 = (List )obj; else if (obj is List ) list3 = (List )obj; else if (obj is List ) list4 = (List )obj;