为什么没有main还能运行，还有怎么能在这个基础上加上数字的日期时间和星期
#include
#include
#define ID_TIMER 1//计时器ID
#define TWOPI (2*3.14159)
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR szCmdLine,int iCmdShow)
{
static TCHAR szAppName[]=TEXT("Clock");
HWND hwnd;
MSG msg;
WNDCLASS wndclass;
wndclass.cbClsExtra=0;
wndclass.cbWndExtra=0;
wndclass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
wndclass.hCursor=LoadCursor(NULL,IDC_ARROW);
wndclass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
wndclass.hInstance=hInstance;
wndclass.lpfnWndProc=WndProc;
wndclass.lpszClassName=szAppName;
wndclass.lpszMenuName=NULL;
wndclass.style=CS_HREDRAW|CS_VREDRAW;
if(!RegisterClass(&wndclass))
{
MessageBox(NULL,TEXT("This program requires Windows NT"),szAppName,MB_ICONERROR);
return 0;
}
hwnd=CreateWindow(szAppName,TEXT("CLOCK"),WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,NULL,NULL,hInstance,NULL);
ShowWindow(hwnd,iCmdShow);
UpdateWindow(hwnd);
while(GetMessage(&msg,NULL,0,0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
void Setsotropic(HDC hdc,int cxClient,int cyClient)
{
SetMapMode(hdc,MM_ISOTROPIC);
SetWindowExtEx(hdc,1000,1000,NULL);
SetViewportExtEx(hdc,cxClient/2,-cyClient/2,NULL);
SetViewportOrgEx(hdc,cxClient/2,cyClient/2,NULL);
}
void RotatePoint(POINT pt[],int iNum,int iAngle)
{
int i;
POINT ptTemp;
for(i=0;i<iNum;i++)
{
ptTemp.x=(int)(pt[i].x*cos(TWOPI*iAngle/360)+pt[i].y*sin(TWOPI*iAngle/360));
ptTemp.y=(int)(pt[i].y*cos(TWOPI*iAngle/360)+pt[i].x*sin(TWOPI*iAngle/360));
pt[i]=ptTemp;
}
}
void DrawClock(HDC hdc)
{
int iAngle;
POINT pt[3];
for(iAngle=0;iAngle<360;iAngle+=6)
{
pt[0].x=0;
pt[0].y=900;
RotatePoint(pt,1,iAngle);
pt[2].x=pt[2].y=iAngle%5?33:100;
pt[0].x-=pt[2].x/2;
pt[0].y-=pt[2].y/2;
pt[1].x=pt[0].x+pt[2].x;
pt[1].y=pt[0].y+pt[2].y;
SelectObject(hdc,GetStockObject(BLACK_BRUSH));
Ellipse(hdc,pt[0].x,pt[0].y,pt[1].x,pt[1].y );
}
}
void DrawHands(HDC hdc,SYSTEMTIME *pst,BOOL fChange)
{
static POINT pt[3][5]={0,-150,100,0,0,600,-100,0,0,-150,
0,-200,50,0,0,800,-50,0,0,-200,
0,0,0,0,0,0,0,0,0,800
};
int i,iAngle[3];
POINT ptTemp[3][5];
iAngle[0]=(pst->wHour*30)%360+pst->wMinute/2;
iAngle[1]=pst->wMinute*6;
iAngle[2]=pst->wSecond*6;
memcpy(ptTemp,pt,sizeof(pt));
for(i=fChange?0:2;i<3;i++)
{
RotatePoint(ptTemp[i],5,iAngle[i]);
Polyline(hdc,ptTemp[i],5);
}
}
LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
static int cxClient,cyClient;
static SYSTEMTIME stPrevious;
BOOL fChange;
HDC hdc;
PAINTSTRUCT ps;
SYSTEMTIME st;
switch(message)
{
case WM_CREATE:
SetTimer(hwnd,ID_TIMER,1000,NULL);
GetLocalTime(&st);
stPrevious=st;
return 0;
case WM_SIZE:
cxClient=LOWORD(lParam);
cyClient=HIWORD(lParam);
return 0;
case WM_TIMER:
GetLocalTime(&st);
fChange=st.wHour!=stPrevious.wHour||st.wMinute!=stPrevious.wMinute;
hdc=GetDC(hwnd);
Setsotropic(hdc,cxClient,cyClient);
SelectObject(hdc,GetStockObject(WHITE_PEN));
DrawHands(hdc,&stPrevious,fChange);
SelectObject(hdc,GetStockObject(BLACK_PEN));
DrawHands(hdc,&st,TRUE);
stPrevious=st;
return 0;
case WM_PAINT:
hdc=BeginPaint(hwnd,&ps);
Setsotropic(hdc,cxClient,cyClient);
DrawClock(hdc);
DrawHands(hdc,&stPrevious,TRUE);
EndPaint(hwnd,&ps);
return 0;
case WM_DESTROY:
KillTimer(hwnd,ID_TIMER);
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd,message,wParam,lParam);
}
