仿MFC实现c 的按名动态创建对象功能

仿MFC实现c++的按名动态创建对象功能.txt性格本身没有好坏，乐观和悲观对这个世界都有贡献，前者发明了飞机，后者发明了降落伞。类似于CObject的基类BaseClass、类似于CRuntimeClass的RuntimeClass和相关宏的定义头文件如下：
//////////////////////////BaseClass.h

#ifndef BASECLASS_H
#define BASECLASS_H

#include

class BaseClass;

struct RuntimeClass
{
char *classname;
BaseClass* (*pCreateFn)();

void* CreateObject();
static RuntimeClass* LoadByName(std::string classname);

static RuntimeClass *pFirstClass;
RuntimeClass *pBaseClass;
RuntimeClass *pNextClass;
};

struct Class_List
{
Class_List(RuntimeClass* pNewClass);
};

#define Runtime_Class(classname) \
(&classname::class##classname)


#define Declare_RTTI(classname) \
public: \
static RuntimeClass class##classname; \
virtual RuntimeClass* GetRuntimeClass() const; \


#define Implement_RTTI(classname,basename) \
static char lpsz##classname[]=#classname; \
RuntimeClass classname::class##classname= \
{ lpsz##classname,NULL,Runtime_Class(basename),NULL}; \
static Class_List _init_##classname(&classname::class##classname); \
RuntimeClass* classname::GetRuntimeClass() const \
{ return &classname::class##classname;} \


#define Declare_DynCreate(classname) \
Declare_RTTI(classname) \
static BaseClass* CreateObject(); \

#define Implement_DynCreate(classname,basename) \
BaseClass* classname::CreateObject() \
{ return new classname; } \
static char lpsz##classname[]=#classname; \
RuntimeClass classname::class##classname= \
{ lpsz##classname,classname::CreateObject,Runtime_Class(basename),NULL}; \
static Class_List _init_##classname(&classname::class##classname); \
RuntimeClass* classname::GetRuntimeClass() const \
{ return &classname::class##classname;} \



class BaseClass
{
public:
virtual RuntimeClass* GetRuntimeClass() const
{
return &BaseClass::classBaseClass;
}
virtual void printClassName() { std::cout<<"BaseClass!\n";}
public:
static RuntimeClass classBaseClass;
};

#endif





//////////////////////////////////////////////////BaseClass.cpp

#include "BaseClass.h"



RuntimeClass* RuntimeClass::pFirstClass=NULL;

static char lpszBaseClass[]="BaseClass";

RuntimeClass BaseClass::classBaseClass ={lpszBaseClass,NULL,NULL,NULL};

static Class_List _init_BaseClass(&BaseClass::classBaseClass);

Class_List::Class_List(RuntimeClass* pNewClass)
{
pNewClass->pNextClass=RuntimeClass::pFirstClass;
RuntimeClass::pFirstClass=pNewClass;
}


void* RuntimeClass::CreateObject()
{
if (pCreateFn == NULL)
{
return NULL;
}

void* pObject = NULL;
pObject = (*pCreateFn)();

return pObject;
}

RuntimeClass* RuntimeClass::LoadByName(std::string

classname)
{
RuntimeClass* pClass;
for (pClass = pFirstClass; pClass != NULL; pClass = pClass->pNextClass)
{
if (strcmp(classname.c_str(), pClass->classname) == 0)
return pClass;
}
return NULL;
}





///////////////////////////////////////////////////////三个测试类ClassA,ClassB,ClassAS

#pragma once
#include "baseclass.h"

class ClassA :
public BaseClass
{
Declare_DynCreate(ClassA)
public:
ClassA(void);
public:
~ClassA(void);
public:
void printClassName()
{
std::cout<<"ClassA!\n";
}
public:
void dosth()
{
std::cout<<"dosth\n";
}
};



#include "ClassA.h"

Implement_DynCreate(ClassA,BaseClass)

ClassA::ClassA(void)
{
}

ClassA::~ClassA(void)
{
}



/////////////////////////

#pragma once
#include "baseclass.h"

class ClassB :
public BaseClass
{
Declare_DynCreate(ClassB)
public:
ClassB(void);
public:
~ClassB(void);
public:
void printClassName()
{
std::cout<<"ClassB\n";
}
};



#include "ClassB.h"

Implement_DynCreate(ClassB,BaseClass)

ClassB::ClassB(void)
{
}

ClassB::~ClassB(void)
{
}


////////////////////////////////////

#pragma once
#include "classa.h"

class ClassAS :
public ClassA
{
Declare_DynCreate(ClassAS)
public:
ClassAS(void);
public:
~ClassAS(void);
public:
void printClassName()
{
std::cout<<"ClassAS\n";
}
};



#include "ClassAS.h"

Implement_DynCreate(ClassAS,ClassA)

ClassAS::ClassAS(void)
{
}

ClassAS::~ClassAS(void)
{
}






////////////////////////////////////////////////////////////////////////测试

#include "BaseClass.h"
#include
#include "ClassA.h"

using namespace std;

#define DOTEST(classname,varname) \
classname *##varname=new classname(); \
varname->dosth(); \




int _tmain(int argc, _TCHAR* argv[])
{
RuntimeClass* prc;
for(prc=RuntimeClass::pFirstClass;prc!=NULL;prc=prc->pNextClass)
{
cout<classname;
if(prc->pBaseClass!=NULL)
cout<<"--"<pBaseClass->classname<else
cout<<"--NULL"<}
getchar();

prc=RuntimeClass::LoadByName("ClassAS");
ClassA* pb=(ClassA*)prc->CreateObject();
pb->printClassName();

DOTEST(ClassA,ca)

getchar();

return 0;
}