Why must an C# interface method implemented in a class be public?

Question

I have a class which inherits an interface. An interface member method is implemented in my class without an access modifier (so, by default it's private ) .

I am getting the error "cannot implement an interface member because it is not public".

Why it is not allowed? Can't I override the accessibility?

Answer 1

Here's an example of why it doesn't make sense to be able to override the visibility:

interface someI {     void doYourWork(); } public class A : someI {     public void doYourWork()     {         //...     } }  public class B : someI {     private void doYourWork()     {         //...     } } void Main() {     List<someI> workers = getWorkers();     foreach(var worker in workers)         worker.doYourWork(); } 

What happens when your worker is of type B? You're calling a method as if it were public, but it's a private method. If you want this functionality, then it's not really a private method is it?

If you only want it to be public when referenced through your interface, then you can define it as such:

public class B : someI {     void someI.doYourWork()     {         //...     } } 

And you end up with this:

var b = new B(); b.doYourWork(); // Not accessible ((someI)b).doYourWork(); // Accessible