深入浅出MFC学习笔记(第三章MFC六大关键技术之仿真消.doc

软件英才网 软件行业驰名招聘网站消息映射机制SDK编程中，一般处理消息的方法就是使用switch/case判断消息的类型，然后进行响应。更模块化的方法是使用第一章介绍的消息映射表的方法，把消息和消息处理函数关联起来。应该为每个需要处理消息的类构建一个消息映射表，并将基类与派生类的消息映射表连接起来。当窗口函数比较消息时，就沿着这条继承路线传递下去。 为了实现这个目的我们仍然使用两个宏，完成这个功能复杂的构建。首先定义一个数据结构：/消息映射表元素类型。struct AFX_MSGMAP_ENTRYUINT nMessage;UINT nCode;UINT nID;UINT nLastID;UINT nSig;AFX_PMSG pfn;struct AFX_MSGMAPAFX_MSGMAP *pBaseMessageMap;/指向基类的本结构。AFX_MSGMAP_ENTRY*lpEntries;/本类的消息映射表。;在定义一个宏：define DECLARE_MESSAGE_MAPstatic AFX_MSGMAP_ENTRY _messageEntries;static AFX_MSGMAP messageMap;virtual AFX_MSGMAP*GetMessageMap()const;该宏相当于在类中声明两个static数据成员和一个虚成员函数。 它们的定义由以下三个宏实现：#define BEGIN_MESSAGE_MAP(class_name,base_class)AFX_MSGMAP*class_name:GetMessageMap()const return &class_name:message;AFX_MSGMAP messageMap= &base_class:messageMap,class_name:_messageEntriesAFX_MSGMAP_ENTRY _messageEntries= #define ON_COMMAND(id,memFunc) WM_COMMAND,0,id,id,AFx_sig_vv ,(AFX_PMSG)memFunc ,#define END_MESSAGE_MAP() 0,0,0,0,AfxSig_end,(AFX_PMSG)0以CView为例，下面的代码：class CWnd :public CWnd public: DECLARE_MESSAGE_MAP();BEGIN_MESSAGE_MAP(CView,CWnd)ON_COMMAND(CViewid,0)END_MESSAGE_MAP()展开后变为：class CView :public CWndpublic:static AFX_MESSAGE_ENTRY _messageEntries;static AFX_MSGMAP messageMap;virtual AFX_MSGMAP*GetMessageMap()const;AFX_MSGMAP*CView:GetMessageMap()const return &CView:messagemMap;AFX_MSGMAP CView:messageMap=&(CWnd:messageMap),(AFX_MSGMAP_ENTRY*)&(CView:_messageEntries);AFX_MSGMAP_ENTRY CView:_messageEntries=WM_COMMAND,0,122,122,1,(AFX_PMSG)0,0,0,0,0,0,(AFX_PMSG)0为了验证整个消息映射表，我们在每个类的消息映射表中添加了一个空的消息，这是为了做点标记，用于标示消息映射表的最后一个消息。MFC当然不是这样实现的。/* CCmdTarget是消息传递的终点，因此在实现时需要特殊处理，这一点容易出错，要特别注意。class CCmdTarget:public CObjectDECLARE_DYNCREATE(CCmdTarget)DECLARE_MESSAGE_MAP()public:CCmdTarget()/coutCCmdTarget constructor!endl;/CreateObject();CCmdTarget()/coutCCmdTarget destructor!endl;public:;IMPLEMENT_DYNCREATE(CCmdTarget,CObject) AFX_MSGMAP CCmdTarget:messageMap= NULL,CCmdTarget:_messageEntries;AFX_MSGMAP_ENTRY CCmdTarget:_messageEntries= 0,0,10,0,AfxSig_end,0, 0,0,0,0,AfxSig_end,0;AFX_MSGMAP*CCmdTarget:GetMessageMap()const return &CCmdTarget:messageMap; 以下为包含动态创建、类型识别、消息映射的完整代码：cpp view plaincopy1 #include 2 #include 3 #include 4 using namespace std; 5 class CCmdTarget; 6 typedef void (CCmdTarget:*AFX_PMSG)(void); 7 8 /消息映射表元素类型。 9 enum AfxSig 10 11 AfxSig_end=0, 12 AfxSig_vv, 13 ; 14 struct AFX_MSGMAP_ENTRY 15 16 UINT nMessage; 17 UINT nCode; 18 UINT nID; 19 UINT nLastID; 20 UINT nSig; 21 AFX_PMSG pfn; 22 ; 23 struct AFX_MSGMAP 24 25 AFX_MSGMAP *pBaseMessageMap;/指向基类的本结构。 26 AFX_MSGMAP_ENTRY*lpEntries;/本类的消息映射表。 27 ; 28 29 30 #define DECLARE_MESSAGE_MAP() 31 public: 32 static AFX_MSGMAP_ENTRY _messageEntries; 33 static AFX_MSGMAP messageMap; 34 virtual AFX_MSGMAP*GetMessageMap()const; 35 36 #define BEGIN_MESSAGE_MAP(class_name,base_class) 37 AFX_MSGMAP*class_name:GetMessageMap()const 38 return &class_name:messageMap; 39 AFX_MSGMAP class_name:messageMap=&base_class:messageMap,class_name:_messageEntries; 40 AFX_MSGMAP_ENTRY class_name:_messageEntries= 41 42 43 #define ON_COMMAND(id,memFunc) 44 WM_COMMAND,0,id,id,AfxSig_vv,(AFX_PMSG)memFunc , 45 46 #define END_MESSAGE_MAP() 47 0,0,0,0,AfxSig_end,(AFX_PMSG)0 48 ; 49 50 51 52 53 class CObject; 54 class CRuntimeClass 55 56 public: 57 char* m_lpszClassName;/对象所属类名 58 int m_nObjectSize;/对象大小 59 int m_wSchema;/模式号 60 CObject*(PASCAL*m_pfnCreateObject)();/构建函数,抽象类为NULL 61 CRuntimeClass *m_pBaseClasss;/基类CRuntimeClass对象指针。 62 static CRuntimeClass *pFirstClass;/链表头指针。static 63 CRuntimeClass *m_pNextClass;/下一指针。 64 public: 65 CObject*CreateObject() 66 67 if(m_pfnCreateObject=NULL) 68 69 cout该类型不支持动态创建！endl; 70 return NULL; 71 72 CObject*pClass=(*m_pfnCreateObject)(); 73 return pClass; 74 75 static CRuntimeClass*Load() 76 77 couts; 80 for(CRuntimeClass*pClass=pFirstClass;pClass;pClass=pClass-m_pBaseClasss) 81 82 if(pClass-m_lpszClassName=s) 83 84 return pClass; 85 86 87 return NULL; 88 89 ; 90 91 class AFX_CLASSINIT 92 93 public: 94 AFX_CLASSINIT(CRuntimeClass*pNewClass)/构造函数 95 96 pNewClass-m_pNextClass=CRuntimeClass:pFirstClass; 97 CRuntimeClass:pFirstClass =pNewClass; 98 99 ; 100 101 /*/ 102 /* 动态类型识别宏定义 103 /与CRuntimeClass类中的构建函数相区别。此处的CreateObject函数在每个类中都以static成员函数存在，用以 104 /初始化类型型录表，而CRuntimeClass中的CreateObject用于调用每个类的构建函数。仅仅是函数名相同罢了。*/ 105 /*/ 106 107 #define DECLARE_DYNAMIC(class_name) 108 public: 109 static CRuntimeClass Class#class_name; 110 virtual CRuntimeClass*GetRuntimeClass()const; 111 112 113 #define DECLARE_DYNCREATE(class_name) 114 DECLARE_DYNAMIC(class_name) 115 static CObject*PASCAL CreateObject(); 116 117 #define RUNTIME_CLASS(class_name) 118 (&class_name:Class#class_name) 119 120 #define _IMPLEMENT_RUNTIMECLASS(class_name,base_class_name,wSchema,pfnNew) 121 class CRuntimeClass class_name:Class#class_name = 122 #class_name, 123 sizeof(class_name),wSchema,pfnNew,RUNTIME_CLASS(base_class_name),NULL; 124 static AFX_CLASSINIT _init#class_name( RUNTIME_CLASS(class_name); 125 CRuntimeClass *class_name:GetRuntimeClass()const 126 return &class_name:Class#class_name;/此处将class_name写成了classname花了一两天才查出来。啊啊啊啊啊。20120605 127 128 129 #define IMPLEMENT_DYNAMIC(class_name,base_class_name) 130 _IMPLEMENT_RUNTIMECLASS(class_name,base_class_name,0xFFFF,NULL) 131 132 #define IMPLEMENT_DYNCREATE(class_name,base_class_name) 133 CObject*PASCAL class_name:CreateObject()return new class_name; 134 _IMPLEMENT_RUNTIMECLASS(class_name,base_class_name,0xFFFF,class_name:CreateObject) 135 136 137 /*/ 138 /* 对CObject特殊处理。 */ 139 /*/ 140 class CObject 141 142 public: 143 CObject() 144 145 /coutCObject constructor!endl; 146 147 CObject() 148 149 /coutCObject destructor!m_pBaseClasss) 159 160 if(pThis=pClass) 161 162 return true; 163 164 165 return false; 166 167 ; 168 class CRuntimeClass CObject: ClassCObject= 169 170 CObject,sizeof(CObject),0xFFFF,NULL,NULL,NULL 171 ; 172 static AFX_CLASSINIT _init_CObject(&CObject: ClassCObject); 173 CRuntimeClass *CObject:GetRuntimeClass() 174 175 return &CObject:ClassCObject; 176 177 CRuntimeClass*CRuntimeClass:pFirstClass=NULL; 178 179 /*/ 180 /* CCmdTarget是消息传递的终点，因此在实现时不能使用BEGIN_MESSAGE_MAP */ 181 /*/ 182 class CCmdTarget:public CObject 183 184 DECLARE_DYNCREATE(CCmdTarget) 185 DECLARE_MESSAGE_MAP() 186 public: 187 CCmdTarget() 188 189 /coutCCmdTarget constructor!endl; 190 /CreateObject(); 191 192 CCmdTarget() 193 194 /coutCCmdTarget destructor!endl; 195 196 public: 197 198 199 ; 200 IMPLEMENT_DYNCREATE(CCmdTarget,CObject) 201 202 AFX_MSGMAP CCmdTarget:messageMap= 203 NULL,CCmdTarget:_messageEntries; 204 AFX_MSGMAP_ENTRY CCmdTarget:_messageEntries= 205 206 0,0,10,0,AfxSig_end,0, 207 0,0,0,0,AfxSig_end,0 208 ; 209 AFX_MSGMAP*CCmdTarget:GetMessageMap()const 210 211 return &CCmdTarget:messageMap; 212 213 214 class CWnd:public CCmdTarget 215 216 DECLARE_DYNCREATE(CWnd) 217 DECLARE_MESSAGE_MAP() 218 public: 219 CWnd() 220 221 /coutCWnd constructorendl; 222 223 CWnd() 224 225 /coutCWnd destructorendl; 226 227 public: 228 virtual bool Create() 229 230 coutCWnd:Createendl; 231 CreateEx(); 232 return true; 233 234 bool CreateEx() 235 236 coutCWnd:CreateExendl; 237 PreCreateWindow(); 238 return true; 239 240 virtual bool PreCreateWindow() 241 242 coutCWnd:PreCreateWindowendl; 243 return true; 244 245 ; 246 IMPLEMENT_DYNCREATE(CWnd,CCmdTarget) 247 248 class CView :public CWnd 249 250 DECLARE_DYNCREATE(CView) 251 DECLARE_MESSAGE_MAP() 252 public: 253 CView() 254 255 /coutCView constructorendl; 256 257 258 CView() 259 260 /coutCView destructorendl; 261 262 263 ; 264 IMPLEMENT_DYNCREATE(CView,CWnd) 265 266 class CFrameWnd:public CWnd 267 268 DECLARE_DYNCREATE(CFrameWnd) 269 DECLARE_MESSAGE_MAP() 270 public: 271 CFrameWnd() 272 273 /coutCFrameWnd constructorendl; 274 275 276 CFrameWnd() 277 278 /coutCFrameWnd destructorendl; 279 280 public: 281 virtual bool Create() 282 283 coutCFrameWnd:Createendl; 284 CreateEx(); 285 return true; 286 287 virtual bool PreCreateWindow() 288 289 coutCFrameWnd:PreCreateWindowendl; 290 return true; 291 292 ; 293 IMPLEMENT_DYNCREATE(CFrameWnd,CWnd) 294 295 class CWinThread:public CCmdTarget 296 297 public: 298 CWinThread() 299 300 /coutCWinThread constructorendl; 301 302 CWinThread() 303 304 /coutCWinThread destructorendl; 305 306 public: 307 virtual bool InitInstance() 308 309 coutCWinThread:InitInstanceendl; 310 return true; 311 312 virtual bool Run() 313 314 coutCWinThread:Runendl; 315 return true; 316 317 ; 318 class CWinApp:public CWinThread 319 320 DECLARE_MESSAGE_MAP() 321 public: 322 CWinApp() 323 324 /coutCWinApp Constructor endl; 325 m_currentApp=this; 326 327 CWinApp() 328 329 /coutCWinApp destructor endl; 330 331 virtual bool InitApplication() 332 333 coutCWinApp:InitApplicationendl; 334 return true; 335 336 337 virtual bool InitInstance() 338 339 coutCWinApp:InitInstanceendl; 340 return true; 341 342 virtual bool Run() 343 344 coutCWinApp:Runendl; 345 return CWinThread:Run(); 346 347 public: 348 CWinApp*m_currentApp; 349 CFrameWnd*m_currentFrameWnd; 350 ; 351 class CDocument:public CCmdTarget 352 353 DECLARE_MESSAGE_MAP() 354 public: 355 CDocument() 356 357 /coutCDocument constructor endl; 358 359 CDocument() 360 361 /coutCDocunment destructor endl; 362 363 ; 364 class CMyFrameWnd:public CFrameWnd 365 366 DECLARE_DYNCREATE(CMyFrameWnd) 367 DECLARE_MESSAGE_M