About the access permissions of protected members

A friend of mine asked me a few days ago why the parent class cannot be accessed in the subclass.ProtectedMethod?

What she saw in a bookCodeProbably as follows:

 

Public Class A

{

Public StringName ="";

Protected IntAge = 0;

}

Public Class AB:A

{

Public VoidInit ()

{

AA =New A();

A. Name ="Lifengguo";

A. Age = 24;

}

}

 

But she is always unable to pass during compilation. She asked me why? My understanding is:

 

ProtectedIs a protected member, which can be accessed in its class and can be accessed by a derived class.

The above sentence contains three meanings:

1,Class itself can be accessed;

2,Can be accessed in the derived class;

3,Class instances are inaccessible.ProtectedMember.

 

The following code is used in the class itselfProtectedMember

Public Class A

{

Public StringName ="";

Protected IntAge = 0;

PublicA ()

{

Name ="Lifengguo";

Age = 24;

}

}

 

The following code is used in the derived classProtectedMember

Public Class AB:A

{

PublicAB ()

{

Base. Name ="Li fengguo";

Base. Age = 24;

}

}

 

The following code is a member of the Instance category class:

Public Class C

{

Public VoidInit ()

{

AA =New A();

ABAB =New AB();

A. Name ="Lifengguo";// OK

AB. Name ="Li fengguo";// OK

A. Age = 24;// Error

AB. Age = 24;// Error

}

}