Win32 message customization

#include <windows.h>#include <process.h>#include <math.h>#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<REP&&pparams->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)

These two sentences are already very obvious. It is interesting to change the message customization !!