Question

The last statement does not compile. please refer to the comments along with the code for the detail of my question.

class Test
{
    private static void Foo(Delegate d){}

    private static void Bar(Action a){}

    static void Main()
    {
        Foo(new Action(() => { Console.WriteLine("a"); })); // Action converts to Delegate implicitly

        Bar(() => { Console.WriteLine("b"); }); // lambda converts to Action implicitly

        Foo(() => { Console.WriteLine("c"); }); // Why doesn't this compile ? (lambda converts to Action implicitly, and then Action converts to Delegate implicitly)
    }
}

Answer 1

Because the .net compiler doesn’t know what type of delegate to turn the lambda into. It could be an Action, or it could be a void MyDelegate().

If you change it as follows, it should work:

Foo(new Action(() => { Console.WriteLine("c"); }));