Question

Is there any way to override a class method with a lambda function?

For example with a class definition of

class MyClass {  
    public virtual void MyMethod(int x) {
        throw new NotImplementedException();
    }
}

Is there anyway to do:

MyClass myObj = new MyClass();
myObj.MyMethod = (x) => { Console.WriteLine(x); };

Answer 1

No. However if you declare the method as a lambda in the first place, you can set it, though I would try to do that at initialization time.

class MyClass {  
    public MyClass(Action<int> myMethod)
    {
        this.MyMethod = myMethod ?? x => { };
    }

    public readonly Action<int> MyMethod;
}

This however cannot implement an interface that has a MyMethod declared, unless the interface specifies a lambda property.

F# has object expressions, which allow you to compose an object out of lambdas. I hope at some point this is part of c#.