Test if an object implements an interface

Question

I have an object parameter and I need to check if the object implements a specified interface in vb.net. How to test this?

Thanks.

Answer 1

Use TypeOf...Is:

If TypeOf objectParameter Is ISpecifiedInterface Then
    'do stuff
End If 

Answer 2

I also found this article by Scott Hansleman to be particularly helpful with this. In it, he recommends

C#

if (typeof(IWhateverable).IsAssignableFrom(myType)) { ... }

I ended up doing:

VB.Net

Dim _interfaceList As List(Of Type) = myInstance.GetType().GetInterfaces().ToList()
If _interfaceList.Contains(GetType(IMyInterface)) Then
   'Do the stuff
End If

Answer 3

requiredInterface.IsAssignableFrom(representedType)

both requiredInterface and representedType are Types

Answer 4

Here is a simple way to determine whether a given object variable "o" implements a specific interface "ISomething":

If o.GetType().GetInterfaces().Contains(GetType(ISomething)) Then
    ' The interface is implemented
End If