MFC.h
#define BOOL int
#define TRUE 1
#define FALSE 0
#define LPCSTR LPSTR
typedef char* LPSTR;
#define UINT int
#define PASCAL _stdcall
#define TRACE1 printf
#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;
class CObject;
struct CRuntimeClass
{
// Attributes
LPCSTR m_lpszClassName;
int m_nObjectSize;
UINT m_wSchema; // schema number of the loaded class
CObject* (PASCAL* m_pfnCreateObject)(); // NULL => abstract class
CRuntimeClass* m_pBaseClass;
CObject* CreateObject();
static CRuntimeClass* PASCAL Load();
// CRuntimeClass objects linked together in simple list
static CRuntimeClass* pFirstClass; // start of class list
CRuntimeClass* m_pNextClass; // linked list of registered classes
};
struct AFX_CLASSINIT
{ AFX_CLASSINIT(CRuntimeClass* pNewClass); };
#define RUNTIME_CLASS(class_name) \
(&class_name::class##class_name)
#define DECLARE_DYNAMIC(class_name) \
public: \
static CRuntimeClass class##class_name; \
virtual CRuntimeClass* GetRuntimeClass() const;
#define DECLARE_DYNCREATE(class_name) \
DECLARE_DYNAMIC(class_name) \
static CObject* PASCAL CreateObject();
#define _IMPLEMENT_RUNTIMECLASS(class_name, base_class_name, wSchema, pfnNew) \
static char _lpsz##class_name[] = #class_name; \
CRuntimeClass class_name::class##class_name = { \
_lpsz##class_name, sizeof(class_name), wSchema, pfnNew, \
RUNTIME_CLASS(base_class_name), NULL }; \
static AFX_CLASSINIT _init_##class_name(&class_name::class##class_name); \
CRuntimeClass* class_name::GetRuntimeClass() const \
{ return &class_name::class##class_name; } \
#define IMPLEMENT_DYNAMIC(class_name, base_class_name) \
_IMPLEMENT_RUNTIMECLASS(class_name, base_class_name, 0xFFFF, NULL)
#define IMPLEMENT_DYNCREATE(class_name, base_class_name) \
CObject* PASCAL class_name::CreateObject() \
{ return new class_name; } \
_IMPLEMENT_RUNTIMECLASS(class_name, base_class_name, 0xFFFF, \
class_name::CreateObject)
class CObject
{
public:
CObject::CObject() {
}
CObject::~CObject() {
}
virtual CRuntimeClass* GetRuntimeClass() const;
BOOL IsKindOf(const CRuntimeClass* pClass) const;
public:
static CRuntimeClass classCObject;
virtual void SayHello() { cout << "Hello CObject \n"; }
};
class CCmdTarget : public CObject
{
DECLARE_DYNAMIC(CCmdTarget)
public:
CCmdTarget::CCmdTarget() {
}
CCmdTarget::~CCmdTarget() {
}
};
class CWinThread : public CCmdTarget
{
DECLARE_DYNAMIC(CWinThread)
public:
CWinThread::CWinThread() {
}
CWinThread::~CWinThread() {
}
virtual BOOL InitInstance() {
return TRUE;
}
virtual int Run() {
return 1;
}
};
class CWnd;
class CWinApp : public CWinThread
{
DECLARE_DYNAMIC(CWinApp)
public:
CWinApp* m_pCurrentWinApp;
CWnd* m_pMainWnd;
public:
CWinApp::CWinApp() {
m_pCurrentWinApp = this;
}
CWinApp::~CWinApp() {
}
virtual BOOL InitApplication() {
return TRUE;
}
virtual BOOL InitInstance() {
return TRUE;
}
virtual int Run() {
return CWinThread::Run();
}
};
class CDocument : public CCmdTarget
{
DECLARE_DYNAMIC(CDocument)
public:
CDocument::CDocument() {
}
CDocument::~CDocument() {
}
};
class CWnd : public CCmdTarget
{
DECLARE_DYNCREATE(CWnd)
public:
CWnd::CWnd() {
cout << "CWnd Constructor \n";
}
CWnd::~CWnd() {
}
virtual BOOL Create();
BOOL CreateEx();
virtual BOOL PreCreateWindow();
void SayHello() { cout << "Hello CWnd \n"; }
};
class CFrameWnd : public CWnd
{
DECLARE_DYNCREATE(CFrameWnd)
public:
CFrameWnd::CFrameWnd() {
cout << "CFrameWnd Constructor \n";
}
CFrameWnd::~CFrameWnd() {
}
BOOL Create();
virtual BOOL PreCreateWindow();
void SayHello() { cout << "Hello CFrameWnd \n"; }
};
class CView : public CWnd
{
DECLARE_DYNAMIC(CView)
public:
CView::CView() {
}
CView::~CView() {
}
};
// global function
CWinApp* AfxGetApp();MY.h
#include <iostream>
#include "mfc.h"
class CMyWinApp : public CWinApp
{
public:
CMyWinApp::CMyWinApp() {
}
CMyWinApp::~CMyWinApp() {
}
virtual BOOL InitInstance();
};
class CMyFrameWnd : public CFrameWnd
{
DECLARE_DYNCREATE(CMyFrameWnd)
public:
CMyFrameWnd();
~CMyFrameWnd() {
}
void SayHello() { cout << "Hello CMyFrameWnd \n"; }
};
class CMyDoc : public CDocument
{
DECLARE_DYNCREATE(CMyDoc)
public:
CMyDoc::CMyDoc() {
cout << "CMyDoc Constructor \n";
}
CMyDoc::~CMyDoc() {
}
void SayHello() { cout << "Hello CMyDoc \n"; }
};
class CMyView : public CView
{
DECLARE_DYNCREATE(CMyView)
public:
CMyView::CMyView() {
cout << "CMyView Constructor \n";
}
CMyView::~CMyView() {
}
void SayHello() { cout << "Hello CMyView \n"; }
};
// global function
void AfxPrintAllClasses();MFC.CPP
#include "my.h" // it should be mfc.h, but for CMyWinApp definition, so...
extern CMyWinApp theApp;
static char szCObject[] = "CObject";
struct CRuntimeClass CObject::classCObject =
{ szCObject, sizeof(CObject), 0xffff, NULL, NULL };
static AFX_CLASSINIT _init_CObject(&CObject::classCObject);
CRuntimeClass* CRuntimeClass::pFirstClass = NULL;
AFX_CLASSINIT::AFX_CLASSINIT(CRuntimeClass* pNewClass)
{
pNewClass->m_pNextClass = CRuntimeClass::pFirstClass;
CRuntimeClass::pFirstClass = pNewClass;
}
CObject* CRuntimeClass::CreateObject()
{
if (m_pfnCreateObject == NULL)
{
TRACE1("Error: Trying to create object which is not "
"DECLARE_DYNCREATE \nor DECLARE_SERIAL: %hs.\n",
m_lpszClassName);
return NULL;
}
CObject* pObject = NULL;
pObject = (*m_pfnCreateObject)();
return pObject;
}
CRuntimeClass* PASCAL CRuntimeClass::Load()
{
char szClassName[64];
CRuntimeClass* pClass;
// JJHOU : instead of Load from file, we Load from cin.
cout << "enter a class name... ";
cin >> szClassName;
for (pClass = pFirstClass; pClass != NULL; pClass = pClass->m_pNextClass)
{
if (strcmp(szClassName, pClass->m_lpszClassName) == 0)
return pClass;
}
TRACE1("Error: Class not found: %s \n", szClassName);
return NULL; // not found
}
CRuntimeClass* CObject::GetRuntimeClass() const
{
return &CObject::classCObject;
}
BOOL CObject::IsKindOf(const CRuntimeClass* pClass) const
{
CRuntimeClass* pClassThis = GetRuntimeClass();
while (pClassThis != NULL)
{
if (pClassThis == pClass)
return TRUE;
pClassThis = pClassThis->m_pBaseClass;
}
return FALSE; // walked to the top, no match
}
BOOL CWnd::Create()
{
return TRUE;
}
BOOL CWnd::CreateEx()
{
PreCreateWindow();
return TRUE;
}
BOOL CWnd::PreCreateWindow()
{
return TRUE;
}
BOOL CFrameWnd::Create()
{
CreateEx();
return TRUE;
}
BOOL CFrameWnd::PreCreateWindow()
{
return TRUE;
}
CWinApp* AfxGetApp()
{
return theApp.m_pCurrentWinApp;
}
IMPLEMENT_DYNAMIC(CCmdTarget, CObject)
IMPLEMENT_DYNAMIC(CWinThread, CCmdTarget)
IMPLEMENT_DYNAMIC(CWinApp, CWinThread)
IMPLEMENT_DYNAMIC(CDocument, CCmdTarget)
IMPLEMENT_DYNCREATE(CWnd, CCmdTarget)
IMPLEMENT_DYNAMIC(CView, CWnd)
IMPLEMENT_DYNCREATE(CFrameWnd, CWnd)MY.CPP
#include "my.h"
CMyWinApp theApp;
BOOL CMyWinApp::InitInstance()
{
m_pMainWnd = new CMyFrameWnd;
return TRUE;
}
CMyFrameWnd::CMyFrameWnd()
{
cout << "CMyFrameWnd Constructor \n";
Create();
}
IMPLEMENT_DYNCREATE(CMyFrameWnd, CFrameWnd)
IMPLEMENT_DYNCREATE(CMyDoc, CDocument)
IMPLEMENT_DYNCREATE(CMyView, CView)
void PrintAllClasses()
{
CRuntimeClass* pClass;
// just walk through the simple list of registered classes
for (pClass = CRuntimeClass::pFirstClass; pClass != NULL;
pClass = pClass->m_pNextClass)
{
cout << pClass->m_lpszClassName << "\n";
cout << pClass->m_nObjectSize << "\n";
cout << pClass->m_wSchema << "\n";
}
}
//---------------------------------------------------------------
// main
//---------------------------------------------------------------
void main()
{
CWinApp* pApp = AfxGetApp();
pApp->InitApplication();
pApp->InitInstance();
pApp->Run();
//Test Dynamic Creation
CRuntimeClass* pClassRef;
CObject* pOb;
while (1)
{
if ((pClassRef = CRuntimeClass::Load()) == NULL)
break;
pOb = pClassRef->CreateObject();
if (pOb != NULL)
pOb->SayHello();
}
}这里用MFC深入浅出FRAME6例子来做讲解：
首先看结果：
接下来进行解析：
CWinApp* pApp = AfxGetApp();
定义 CWinApp指针 pApp指向 AfxGetApp()的返回值theApp.m_pCurrentWinApp;
对theApp.m_pCurrentWinApp;进行展开：
theApp为CMyWinApp 的对象，
CMyWinApp类结构如下：
class CMyWinApp : public CWinApp
{
public:
CMyWinApp::CMyWinApp() {
}
CMyWinApp::~CMyWinApp() {
}
由结构可以得知没有m_pCurrentWinApp;所以查找父类
父类CWinApp定义如下：
class CWinApp : public CWinThread
{
DECLARE_DYNAMIC(CWinApp)
public:
CWinApp* m_pCurrentWinApp;
CWnd* m_pMainWnd;
public:
CWinApp::CWinApp() {
m_pCurrentWinApp = this;
}
CWinApp::~CWinApp() {
}
virtual BOOL InitApplication() {
return TRUE;
}
virtual BOOL InitInstance() {
return TRUE;
}
virtual int Run() {
return CWinThread::Run();
}
};
由此可以知道m_pCurrentWinApp是一个CWinApp类指针；
方便了解CWinApp类先对类中DECLARE_DYNAMIC()进行扩展；
已知存在巨集#define DECLARE_DYNAMIC(class_name) \
public: \
static CRuntimeClass class##class_name; \
virtual CRuntimeClass* GetRuntimeClass() const;
DECLARE_DYNAMIC(CWinApp)=
public ：\
带入CWinApp类中，得知完整定义为:
class CWinApp : public CWinThread
{
public:
static CRuntimeClass classCWinAPP;
virtuial CRuntimeClass *GetRuntimeClass() const;
CWinApp* m_pCurrentWinApp ;CWnd* m_pMainWnd;
public:
CWinApp::CWinApp() {
m_pCurrentWinApp = this;
}
CWinApp::~CWinApp() {
}
virtual BOOL InitApplication() {
return TRUE;
}
virtual BOOL InitInstance() {
return TRUE;
}
virtual int Run() {
return CWinThread::Run();
}
};
ok 那么我们就知道pApp就直指向当前类CMyWinApp类父类CWinApp的一个this指针。
从而
pApp->InitApplication();
pApp->InitInstance();
pApp->Run();
所实现的就是this->InitApplication();this->InitInstance();;this->Run();
对上述函数进行展开得到的结果就是:return TRUE ; return TRUE;以及return CWinThread::Run();
然后查看CWinThread::Run();发现结果就是return 1；
这样看会不会太累了，对的~我们可以将继承关系做成一下图解：
首先看初始化过程：pApp->InitInstance();产生的结果CWnd Constructor CFrameWnd Constructor CMyFrameWnd Constructor 从上图可以看到CWinApp 继承CWinTread类，理论上和CWnd，CFrameWnd及CMyFrameWnd八竿子打不到。
那在哪些环节可以动态关联呢？
最后可以找到以下语句：
BOOL CMyWinApp::InitInstance()
{
m_pMainWnd = new CMyFrameWnd;
return TRUE;
}
是不是很刺激..你可以将这句话//就会发现不再产生结果CWnd Constructor CFrameWnd Constructor CMyFrameWnd Constructor ，居然CMyFrameWnd出现了，对应CWnd->CFrameWnd->CMyFrameWnd的家族体系就牵引而出，那么又有一个问题，CMyWinApp可是CWinApp的派生类呀~CWinApp指向的可是CMyWinApp的父类InitInstance()，然后探索会发现：
CWinApp* pApp = AfxGetApp();
CWinApp* AfxGetApp()
{
return theApp.m_pCurrentWinApp;
}
CMyWinApp theApp;
m_pCurrentWinApp = this;
原来折腾半天 pApp指向的是派生类的this....这个弯绕的有点大~不过总算是出来了；
然后进入CRuntimeClass::Load()环节..这个就是找到类属于我们这个体系，不多说
然后进入pOb = pClassRef->CreateObject();
这个的本质是查看类中是否存在DECLARE_DYNCREATE(class_name)聚集，存在该巨集的类都是可以动态生成的。
所以输入CObject和 CView类的时候会出现m_pfnCreateObject==NULL的现象因为，无DECLARE_DYNCREATE也就无
自身的static CObject* PASCAL CreateObject();从而为空也在预料之中。