How do I dynamically create an instance of an object when passed the name of the object as a String? (VB.NET)

I have a class library that contains a number of classes. I would like to dynamically create an instance of one of these classes, set its properties, and call a method.

Example:

Public Interface IExample
    Sub DoSomething()
End Interface

Public Class ExampleClass
    Implements IExample

    Dim _calculatedValue as Integer

    Public Property calculatedValue() as Integer
        Get
            return _calculatedValue
        End Get
        Set(ByVal value As Integer)
            _calculatedValue= value
        End Set
    End Property        

    Public Sub DoSomething() Implements IExample.DoSomething
        _calculatedValue += 5
    End Sub
End Class

Public Class Example2
    Implements IExample

    Dim _calculatedValue as Integer

    Public Property calculatedValue() as Integer
        Get
            return _calculatedValue
        End Get
        Set(ByVal value As Integer)
            _calculatedValu开发者_StackOverflowe = value
        End Set
    End Property        

    Public Sub DoSomething() Implements IExample.DoSomething
        _calculatedValue += 7
    End Sub
End Class

So, I want to then create code as follows.

Private Function DoStuff() as Integer
    dim resultOfSomeProcess as String = "Example2"

    dim instanceOfExampleObject as new !!!resultOfSomeProcess!!! <-- this is it

    instanceOfExampleObject.calculatedValue = 6
    instanceOfExampleObject.DoSomething()

    return instanceOfExampleObject.calculatedValue
End Function

Example1 and Example2 may have different properties, which I need to set...

Is this doable?

You can use Activator.CreateInstance for this. The easiest way (IMO) is to first create a Type object and pass that to Activator.CreateInstance:

Dim theType As Type = Type.GetType(theTypename)
If theType IsNot Nothing Then
    Dim instance As IExample = DirectCast(Activator.CreateInstance(theType), IExample)
    ''# use instance
End If

Note though that the string containing the type name must contain the full type name, including the namespace.

If you need to access more specialized members on the types, you will still need to cast them (unless VB.NET has incorporated something similar to dynamic in C#, which I am not aware of).