Question

i have a sub with this signature

Public Sub Save(ByVal obj As IPta) 

now i want the create a instance of Generic.PtaDao(of T) with the type of obj, which could be anything that inherits from my base class Pta

how can i do that? i already found a c# example Declare a generic type instance dynamically

but i dont understand how to implement this in my case.

tia

-edit-

to clearify

lets pretend obj is a object of type Address (Address inherits from Pta so it implements IPta)

now i want to create a new PtaDao object that takes Address objects for example

Dim AddressDao as New Generic.PtaDao(of Address) 

but i want to do this dynamically so if obj is of type UserGroup it should create a PtaDao(of UserGroup)

Answer 1

Make it a generic method, taking an instance of the type parameter as one of the parameters, and constrain the type parameter to have a public parameterless constructor and to implement IPta:

Public Sub Save(Of T As { IPta, New })(ByVal obj As T)     Dim foo As New T     ' Do more stuff here End Sub