C# Singleton Class

A generic base class allowing you to efficiently handle the single-instance creation and initialization. Turn any type into a singleton by extending the Singleton class.

Due to the tradeoffs associated with creating a generic singleton base class, it is not possible to set your constructor to private in the class that inherits from it. Therefore it will not be a true singleton but will allow for other flexibility advantages such as unit testing. It is left to the developer to uphold the integrity of the pattern.

Getting Started

Suppose you have an instance called BusinessLogicClass:

public class BusinessLogicClass {
  public void DoSomeLogic() {
    // ...
  }
}

Singleton

Now we want to treat our BusinessLogicClass class like a singleton. Simply make it inherit from Singleton as follows:

public class BusinessLogicClass : Singleton<BusinessLogicClass> {
  public void DoSomeLogic() {
    // ...
  }
}

Now you will be able to call BusinessLogicClass.Instance.DoSomeLogic(); as a single instance.

Singleton with interface

You also have the ability to specify an interface that your type must implement:

public class BusinessLogicClass : Singleton<BusinessLogicClass, IBizInterface>, IBizInterface {
  public void DoSomeLogic() {
    // ...
  }
}