C# Language Specification

Access to private and protected members of the containing type

A nested type has access to all of the members that are accessible to its containing type, including members of the containing type that have private and protected declared accessibility. The example

using System;

class C
{
private static void F() {
Console.WriteLine("C.F");
}

public class Nested

{
public static void G() {
F();
}
}
}

class Test

{
static void Main() {
C.Nested.G();
}
}

shows a class C that contains a nested class Nested. Within Nested, the method G calls the static method F defined in C, and F has private declared accessibility.

A nested type also may access protected members defined in a base type of its containing type. In the example

using System;

class Base
{
protected void F() {
Console.WriteLine("Base.F");
}
}

class Derived: Base

{
public class Nested
{
public void G() {
Derived d = new Derived();
d.F(); // ok
}
}
}

class Test

{
static void Main() {
Derived.Nested n = new Derived.Nested();
n.G();
}
}

the nested class Derived.Nested accesses the protected method F defined in Derived’s base class, Base, by calling through an instance of Derived.

6.