Can I instantiate a type based on a value in web.config?

Question

I have 2 classes both inherit from the same interface. i want sometimes to run the website using one class and sometimes with another one. Want to decide which one to use based on a configuration value. Can i use web.config to decide which class to create the current instance from?

Answer 1

Yes.

Create a factory method that returns an object of type IMyInterface. Pass in the config value as a parameter to determine which concrete object to create.

IMyInterface FactoryMethod(string configValue)

Answer 2

Indeed you can. Of interest to you is the field AssemblyQualifiedName of Type. So get your type and do:

myObj.GetType().AssemblyQualifiedName

And write the result of this into your config:

<add key="TypeName" Value="...." />

Then, you'll need to consider what constructors it has, and it can be loaded like so:

Type.GetType("...").GetConstructor(...).Invoke(...);