In C#, is it possible to get the owner object's properties from an anonymous function that is assigned outside?

Question

Let's assume we have a class defined as:

class A
{
    public int Param { get; set; }
    public Action DoSomething { get; set; }
}

The DoSomething action is assigned in another class, but it needs to have access to param:

class B
{
    public B()
    {
        var a = new A()
        {
            Param = 100,
            DoSomething = () => Debug.Print( xxx ) // xxx here needs to refer to Param
        };
    }
}

Clearly, this.Param won't work because this is lexically bond to class B. How can I make DoSomething to access its owner class's other properties?

Answer 1

A simple solution is to take a parameter representing Param

class A
{
    public int Param { get; set; }
    public Action<int> DoSomething { private get; set; }
    void RunDoSomething() => DoSomething(Param);
}
...
var a = new A()
{
    Param = 100,
    DoSomething = param => Debug.Print( param ) 
};

Or you could use an Action<A> to essentially get an this reference.