Compiling...
mm.cpp
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(42) : error C2039: 'base2' : is not a member of 'b22'
        d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(36) : see declaration of 'b22'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(42) : error C2385: 'kk::lby' is ambiguous
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(42) : warning C4385: could be the 'lby' in base 'base' of base 'base1' of base 'b12' of class 'kk'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(42) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b12' of class 'kk'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(42) : warning C4385: or the 'lby' in base 'base' of base 'base1' of base 'b22' of class 'kk'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(42) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b22' of class 'kk'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(44) : error C2039: 'base2' : is not a member of 'b22'
        d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(36) : see declaration of 'b22'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(44) : error C2385: 'kk::lby' is ambiguous
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(44) : warning C4385: could be the 'lby' in base 'base' of base 'base1' of base 'b12' of class 'kk'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(44) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b12' of class 'kk'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(44) : warning C4385: or the 'lby' in base 'base' of base 'base1' of base 'b22' of class 'kk'
d:\program files\microsoft visual studio\myprojects\mb\mm.cpp(44) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b22' of class 'kk'
执行 cl.exe 时出错.

mm.obj - 1 error(s), 0 warning(s)
我的不行，不知为何？？

你应该是把版主的代码复制上去进行编译吧？为什么不换一些新的方法来尝试？我现在都是用新版本的C++资料书了，所以我刚才贴上来的那些代码还算是比较新的，我自己写的那些代码还符合你的要求吧？并且我自己写的那些代码我都在VC和VS2012上调试过了，没有错

--------------------Configuration: aaaaa - Win32 Debug--------------------
Compiling...
aaaaa.cpp
c:\windows\system32\aaaaa.cpp(17) : error C2039: 'base2' : is not a member of 'b22'
        c:\windows\system32\aaaaa.cpp(11) : see declaration of 'b22'
c:\windows\system32\aaaaa.cpp(17) : error C2385: 'kk::lby' is ambiguous
c:\windows\system32\aaaaa.cpp(17) : warning C4385: could be the 'lby' in base 'base' of base 'base1' of base 'b12' of class 'kk'
c:\windows\system32\aaaaa.cpp(17) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b12' of class 'kk'
c:\windows\system32\aaaaa.cpp(17) : warning C4385: or the 'lby' in base 'base' of base 'base1' of base 'b22' of class 'kk'
c:\windows\system32\aaaaa.cpp(17) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b22' of class 'kk'
c:\windows\system32\aaaaa.cpp(19) : error C2039: 'base2' : is not a member of 'b22'
        c:\windows\system32\aaaaa.cpp(11) : see declaration of 'b22'
c:\windows\system32\aaaaa.cpp(19) : error C2385: 'kk::lby' is ambiguous
c:\windows\system32\aaaaa.cpp(19) : warning C4385: could be the 'lby' in base 'base' of base 'base1' of base 'b12' of class 'kk'
c:\windows\system32\aaaaa.cpp(19) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b12' of class 'kk'
c:\windows\system32\aaaaa.cpp(19) : warning C4385: or the 'lby' in base 'base' of base 'base1' of base 'b22' of class 'kk'
c:\windows\system32\aaaaa.cpp(19) : warning C4385: or the 'lby' in base 'base' of base 'base2' of base 'b22' of class 'kk'
Error executing cl.exe.

aaaaa.obj - 4 error(s), 8 warning(s)
我复制了版主的代码去调试，有4个错误，你不妨可以看看我的代码，应该还蛮好理解的，都是一步一步来的

上面就是复制的结果，并且如果删去
// bbb.b22::base2::lby = 1999;
    // 或
    //bbb.b22::base2::base::lby = 1999;
这两句就能编译通过，难道是我的编译器有问题。

对了，对于二重深度的访问，形如。A.BB1::F(),A.BB2::F()这样的表达式是没有问题的。但是再写下去三重深度
A.BB1::CCC1::F()这样类型的表达式的形式就不行了。

我想问一下楼主用的是哪本书？如果在类的多重继承里面，那个说法就不一定了，今晚再举个例子跟你说

#include<iostream>
using namespace std;
class B0            //声明基类B0
{
public:
    B0(int n):nV(n){cout<<"B0的构造函数被调用"<<endl;}
    void fun(){cout<<"member of B0"<<endl;}
    int nV;
};
class B1:virtual public B0   //定义派生类B1，B0是B1的虚基类
{
public:
    B1(int n,int a):B0(n){nV1=a;cout<<"B1的构造函数被调用"<<endl;}
protected:
    int nV1;
};
class B2:virtual public B0  //定义派生类B2，B0是B2的虚基类
{
public:
    B2(int n,int b):B0(n),nV2(b){cout<<"B2的构造函数被调用"<<endl;}
protected:
    int nV2;
};
class D1:public B1,public B2  //定义多重继承的派生类D1
{
protected:
    int nVd;
public:
    D1(int n,int a,int b,int c):B0(n),B1(n,a),B2(n,b),nVd(c){cout<<"D1的构造函数被调用"<<endl;}
    void fun()
    {
        cout<<"member of D1"<<endl;
        cout<<"nV:"<<nV<<endl
            <<"nV1:"<<nV1<<endl
            <<"nV2:"<<nV2<<endl
            <<"nVd:"<<nVd<<endl;
    }
};
void main()
{
    D1 d1(1,2,3,4);
    d1.B0::fun();   //通过派生类对象d1调用基类B0的成员函数
    d1.fun();
    d1.nV=2;        //通过d1调用基类B0的数据成员进行赋值
    cout<<"nV change to:"<<d1.nV<<endl;
}

以上的代码是出自现在最新的C++教材，对于多重继承方面的问题，如果想要调用基类的某个成员函数，可以通过派生类，例如d1.B0::fun(); 就算有多少多重继承，都是差不多这样的，根本不需要像楼主你所说的A.B::C::fun(),既然是继承过来的，若想通过派生类A来调用基类C的fun(),就不需要中间的那个B，直接是A.C::fun()