Can anyone explain how the Strategy Pattern relates to Inversion of Control?

Question

Can anyone explain exactly how the Strategy Pattern relates to Inversion of Control?

Answer 1

When you use the strategy pattern, you want your other classes to depend on the interface rather than a concrete strategy. One way to do this is to have the concrete strategy injected into a class that uses it as the interface rather than having the class understand how to create the appropriate strategy. This is where IoC/Dependency Injection comes in.

The idea would be that you have some sort of configuration or decision class that defines which strategies to use. This could be an IoC framework, but it doesn't necessarily have to be. This class is responsible for configuring your other classes with the appropriate strategy based on system state or configuration. The concrete strategy is created and injected via a constructor or property settor and thus "control" over which strategy class is instantiated is "inverted" -- it is not done by the class depending on it but, rather, from outside.

Answer 2

On its own, the pattern does not introduce inversion of control. If the developer of the pattern implements it such that the swappable algorithm is injected into the controller, then that is inversion. If the implementor, on the other hand, gets the algorithm to use from some other source (such as configuration, or determines it in the constructor of the controller via some other means), then it's just your run-of-the-mill type of code.

Answer 3

No IOC is a different thing all together , you can read more about IOC and DI here top get the actual idea

http://www.codeproject.com/KB/aspnet/IOCDI.aspx