Question

I structured my class like this:

public class MyList: List<MyClass>
{
    internal static bool isConfigured;

    // singleton
    public MyList()
    {
        if (!MyList.isConfigured)
        {
            lock ("isConfigured")
            {
                if (!MyList.isConfigured)
                {
                    // add some elements to MyList parsing them from an XML
                    [..]

                    MyList.isConfigured = true;
                }
            }
        }
    }

    public static MyClass MyStaticMethod(int argument)
    {
        foreach (MyClass c in new MyList())
        {
            // do something
        }
        return // an instance of MyClass
    }

}

When I call MyList.MyStaticMethod() from outside the singleton, I get the following exception:

[..]
MyClass mc = MyList.MyStaticMethod(1));
[..]

An object reference is required for the non-static field, method, or property 'MyList.get'

How can I solve this problem? What is the best why to lay down a singleton class based on List? Thanks

Answer 1

Like any other singleton.

public class MyList: List<MyClass> {
  private readonly static MyList instance = new MyList();

  private MyList() { }

  public static MyList Instance 
  { 
    get 
    {
       return instance;
    }
  }
}