使用方法作为参数调用基础构造函数

Question

I am a beginner in C# and cannot find out how to call a base constructor from within a subclass:

Base class:

public class LookupScript
{
    protected Func<IEnumerable> getItems;

    protected LookupScript()
    {
        //
    }

    public LookupScript(Func<IEnumerable> getItems) : this()
    {
        Check.NotNull(getItems, "getItems");
        this.getItems = getItems;
    }

My derived class:

public class PresenceLookup : LookupScript
{
    public PresenceLookup() :base(??)
    {
     //
    }
    List<string> myMethod()
    {
        return null;
    }

How can I pass myMethod to the base class?

Thank you

Answer 1

You can't, as myMethod is an instance method, and you can't access anything to do with the instance being created within the constructor initializer. This would work though:

public class PresenceLookup : LookupScript
{
    public PresenceLookup() : base(MyMethod)
    {
    }

    private static List<string> MyMethod()
    {
        return null;
    }
}

That uses a method group conversion to create a Func<List<string>> that will call MyMethod .

Or if you don't need the method for anything else, just use a lambda expression:

public class PresenceLookup : LookupScript
{
    public PresenceLookup() : base(() => null)
    {
    }
}