子类怎么用父类的成员函数？
我这样写出错，错误为：
"2248: 'Echo_A ' : cannot access public member declared in class 'A ' "
(指向倒数第3行)

请问这是什么原因？如何改？

#include <iostream>
using namespace std;

class A
{
protected:
int m_a;
public:
A();
void Echo_A();
};

A::A()
{
m_a=1;
}

void A::Echo_A()
{
cout < < "m_a= " < <m_a < <endl;
}

class A1 : A
{
};


int main()
{
A1 a1;
a1.Echo_A();

return 0;
}

[解决办法]
class A1 : public A
{
public:
A1(){}
~A1(){}
};
[解决办法]
class A1 : A
{
};

==============>

class A1 : public A
{
};

如果你不加pulic,默认是private继承,这样子类就不能访问父类的函数了.

[解决办法]
class A1 :public A
{
};