c# - 'protected' 和 'protected internal' 有什么区别？

Question

有人可以解释一下 C# 中 protected 和 protected internal 修饰符之间的区别吗？看起来他们的行为是相同的。

Answer 1

“protected internal”访问修饰符是“protected”和“internal”修饰符的联合。

来自 MSDN, Access Modifiers (C# Programming Guide) :

protected :

The type or member can be accessed only by code in the same class or struct, or in a class that is derived from that class.

internal :

The type or member can be accessed by any code in the same assembly, but not from another assembly.

protected 内部:

The type or member can be accessed by any code in the assembly in which it is declared, OR from within a derived class in another assembly. Access from another assembly must take place within a class declaration that derives from the class in which the protected internal element is declared, and it must take place through an instance of the derived class type.

请注意:protected internal 表示“protected OR internal”(同一程序集中的任何类，或任何派生类 - 即使它在不同的程序集中)。

...为了完整起见:

private :

The type or member can be accessed only by code in the same class or struct.

public :

The type or member can be accessed by any other code in the same assembly or another assembly that references it.

private protected :

Access is limited to the containing class or types derived from the containing class within the current assembly.
(Available since C# 7.2)