#include 
    
     #include 
     
      #include 
      
       #define CLSNAME "Bigjob1"#define WNDNAME "yanshi"#define REP 1000000#define STATUS_READY 0#define STATUS_WORKING 1#define STATUS_DONE 2#define WM_CALC_DONE (WM_USER+0)#define WM_CALC_ABORTED (WM_USER+1)typedef struct{	HWND hwnd;	BOOL bContinue;}PARAMS,*PPARAMS;LRESULT APIENTRY WindowProc(HWND hwnd,							UINT uMsg,							WPARAM wParam,							LPARAM lParam							);int WINAPI WinMain (HINSTANCE hInstance,					HINSTANCE hPrevInstance,					PSTR szCmdLine, 					int iCmdShow){	static TCHAR clsname[] = TEXT(CLSNAME);	WNDCLASS wndclass;	wndclass.style = CS_HREDRAW | CS_VREDRAW ;	wndclass.lpfnWndProc = WindowProc ;	wndclass.cbClsExtra = 0 ;	wndclass.cbWndExtra = 0 ;	wndclass.hInstance = hInstance ;	wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;	wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;	wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;	wndclass.lpszMenuName = NULL ;	wndclass.lpszClassName = clsname ;	if(!::RegisterClass(&wndclass))	{		MessageBox ( NULL, 			TEXT ("This program requires Windows NT!"),			clsname, 			MB_ICONERROR) ;		return 0 ;	}	HWND hwnd;	hwnd = ::CreateWindow(clsname,TEXT(WNDNAME),		WS_OVERLAPPEDWINDOW,		CW_USEDEFAULT,CW_USEDEFAULT,		CW_USEDEFAULT,CW_USEDEFAULT,		NULL,NULL,hInstance,NULL);	::ShowWindow(hwnd,SW_SHOW);	::UpdateWindow(hwnd);	MSG msg;	while(::GetMessage(&msg,NULL,0,0)){		::TranslateMessage(&msg);		::DispatchMessage(&msg);	}	return msg.wParam;}VOID Thread(PVOID pvoid){	double A = 1.0;	INT i;	LONG lTime;	volatile PPARAMS pparams;	pparams = (PPARAMS)pvoid;	lTime = ::GetCurrentTime();	for(i=0; i
       
        bContinue; i++)		A = ::tan(atan(exp(log(sqrt(A*A)))))+1.0;	if(i == REP)	{		lTime = ::GetCurrentTime();		::SendMessage(pparams->hwnd,WM_CALC_DONE,0,lTime);	}	else		::SendMessage(pparams->hwnd,WM_CALC_ABORTED,0,0);	::_endthread();}LRESULT APIENTRY WindowProc(HWND hwnd,							UINT uMsg,							WPARAM wParam,							LPARAM lParam							){	static INT iStatus;	static LONG lTime;	static PARAMS params;	static TCHAR * szMessage[] = 	{TEXT("ready(left mouse button begins)"),	TEXT("working(right mouse button ends)"),	TEXT("%d repetitions in %d msec")};	HDC hdc;	PAINTSTRUCT ps;	RECT rect;	TCHAR szBuffer[64];	switch(uMsg)	{	case WM_LBUTTONDOWN:		if(iStatus == STATUS_WORKING)		{			::MessageBeep(0);			return 0;		}		iStatus = STATUS_WORKING;		params.hwnd = hwnd;		params.bContinue = TRUE;		::_beginthread(Thread,0,&params);		::InvalidateRect(hwnd,NULL,TRUE);		return 0;	case WM_RBUTTONDOWN:		params.bContinue = FALSE;		return 0;	case WM_CALC_DONE:		lTime =lParam;		iStatus = STATUS_DONE;		::InvalidateRect(hwnd,NULL,TRUE);		return 0;	case WM_CALC_ABORTED:		iStatus = STATUS_READY;		::InvalidateRect(hwnd,NULL,TRUE);		return 0;	case WM_DESTROY:		::PostQuitMessage(0);		return 0;	case WM_PAINT:		hdc = ::BeginPaint(hwnd,&ps);		::GetClientRect(hwnd,&rect);		::wsprintf(szBuffer,szMessage[iStatus],REP,lTime);		::DrawText(hdc,szBuffer,-1,&rect,DT_SINGLELINE|			DT_CENTER|DT_VCENTER);		::EndPaint(hwnd,&ps);		return 0;	}	return ::DefWindowProc(hwnd,uMsg,wParam,lParam);}
       
      
     
    

#define WM_CALC_DONE (WM_USER+0)

#define WM_CALC_ABORTED (WM_USER+1)

这两句已经很明显了，可以自定义消息那改多有趣啊！！