访问派生类中的受保护成员 [英] Accessing protected members in derived class

问题描述

在CLI/C ++中，派生类可以访问受保护的基类成员吗?
以下代码导致错误C2248

In CLI/C++, can a derived class access protected members of based class?
The following code results in error C2248

class B;
Class A{
  protected :
         B b;
         int m;
};
private class C : A
{
  public:
         void method();
}
C::method()
{
      A::m; //  error C2248 : m : cannot access protected members declared
in class A
   
}

推荐答案

由于受保护，因此可以通过protected的定义在派生类中对其进行访问.不要写"B->m"，只使用m.

顺便说一句，您的问题是关于CLI/C ++的，这是我不熟悉的某种语言. :)我知道C ++和C ++/CLI.您的代码是关于C ++的.
您的代码显示9个错误，而您所描述的都不是！
你想骗谁我想，你自己.要准确！
如果您不相信它，请尝试按原样对其进行编译.

由于您的代码"几乎每行都包含一个错误，因此我看不到修复它的原因. 不懂你学到的东西！"

—SA

As they are protected they are accessible in the derived class by definition of protected. Don''t write "B->m", use just m.

By the way, your question is about CLI/C++, some language I am not familiar with. :) I know C++ and C++/CLI. You code is about C++.
Your code shows 9 errors, none of then is the one you describe!
Who are you trying to fool? I think, yourself. Be accurate!
If you don''t believe it, try to compile it as is.

As your "code" contains a bug in almost every line, I cannot see a reason to fix it. "Unlearn what you have learned!"

—SA

正如SA所说，您的代码未使用任何C ++/CLI，并且粘贴的内容甚至都不会编译.这是将要编译的固定版本，尽管它与C ++/CLI无关:

As SA said, your code did not use any C++/CLI and what you pasted will not even compile. Here''s the fixed version that will compile, although it has nothing to do with C++/CLI:

class B{};

class A
{
protected :
  B b;
  int m;
};

private class C : A
{
public:
  void method();
};

void C::method()
{
  A::m;
}

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