A very broad question but will give you the first reason that popped into my head for use of a Singleton
.
A Singleton is more appropriate than a dedicated static class when you need to manage the lifetime of some cached objects. Singletons are perfect when you want to refresh state without having to worry about thread safety, for example if you have a class that is being used as a singleton and it has many cached properties or lists that incoming requests may want access to.
The Refresh()
method can simply be setting the current instance to a new instance and not having to refresh individual properties of the class:
private static YourClass instance = new YourClass(); // first instance
public static void Refresh(){
instance = new YourClass(); // creates a new, refreshed instance while not needing to worry about thread safety
}
public static YourClass Instance{
get{
return instance;
}
}