Trainer-use Windows SDK to write a simple clock

Experts on the Internet say that learning programming must be at the underlying level, and I will also learn it.

# Include <windows. h>
# Include <math. h>

# Define PI 3.1415926535
# Define idt_tm1 1
Struct time_point {
Int X;
Int y;
Char s [2];
}; // This is the time point structure on the clock disk.

Lresult callback windproc (hwnd, uint, wparam, lparam );
Int winapi winmain (hinstance, hinstance hprevinstance, lpstr lpcmdline, int nshowcmd );
Bool init_wndclass (hinstance );
Bool init_window (hinstance, int nshowcmd );

Hwnd _ hwnd;
Wndclass _ windclass;
MSG _ MSG;
Tchar _ clsname [] = "sunjoy class ";

Bool init_wndclass (hinstance ){
 
_ Windclass. Style = cs_hredraw | cs_vredraw;
_ Windclass. hinstance = hinstance;
_ Windclass. lpfnwndproc = windproc;
_ Windclass. cbclsextra = 0;
_ Windclass. cbwndextra = 0;
_ Windclass. hbrbackground = (hbrush) getstockobject (white_brush );
_ Windclass. hcursor = loadcursor (null, idc_arrow );
_ Windclass. hicon = loadicon (null, idi_application );
_ Windclass. lpszclassname = _ clsname;
_ Windclass. lpszmenuname = NULL;
 
Return (registerclass (& _ windclass )! = NULL );
}

Bool init_window (hinstance, int nshowcmd ){
_ Hwnd = createwindow (_ clsname,
"Simple Clock ",
Ws_overlappedwindow,
Cw_usedefault,
Cw_usedefault,
450,
450,
NULL,
NULL,
HInstance,
NULL );
ShowWindow (_ hwnd, nShowCmd );
Return (UpdateWindow (_ hwnd )! = NULL );
}

Int WINAPI WinMain (HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
Int nShowCmd)
{
If (! Init_WndClass (hInstance) |! Init_WINDOW (hInstance, nShowCmd )){
MessageBox (NULL, "Create window error", NULL, NULL );
}

 
 
While (GetMessage (& _ msg, NULL, 0, 0 )){
TranslateMessage (& _ msg );
DispatchMessage (& _ msg );
}
Return _ msg. wParam;
}

Lresult callback WindProc (HWND _ hwnd,
UINT _ message,
WPARAM _ wparam,
LPARAM _ lparasm)
{
HDC hdc;
HPEN hpen;
HBRUSH hbrush;
PAINTSTRUCT ps;
Int cx = 220; // x coordinate of the center
Int cy = 215; // y coordinate of the center
Int r = 200; // radius of the circle
TIME_POINT tmp [12]; // time
Int I = 0;
SYSTEMTIME running m; // system time
For (I = 0; I <12; I ++ ){
Tmp [I]. x = (int) (cx + (R-10) * sin (I * PI/6 ));
Tmp [I]. y = (int) (cy-(R-10) * cos (I * PI/6 ));
Wsprintf (TMP [I]. S, "% d", I );
}
Strcpy (TMP [0]. S, "12"); // initialize the coordinates of the clock disk.
 
Switch (_ message ){
Case wm_create:
Settimer (_ hwnd, idt_tm1, 1000, null );
Return 0;
Case wm_paint:

HDC = beginpaint (_ hwnd, & PS );
Hpen = createpen (ps_solid, 2, RGB (0, 0 ));
SelectObject (HDC, Hpen );
Movetoex (HDC, CX, Cy, null );
ARC (HDC, CX-R, cy-R, R + cx, R + cy, cx + R, Cy, cx + R, CY); // draw a clock Disc
For (I = 0; I <12; I ++ ){
Textout (HDC, TMP [I]. x-5, TMP [I]. y-8, TMP [I]. S, strlen (TMP [I]. s ));
} // Initialize the clock Disk
Deleteobject (Hpen );

// White
Hbrush = (HBRUSH) GetStockObject (WHITE_BRUSH );
Hpen = CreatePen (PS_SOLID, 1, RGB (255,255,255 ));
SelectObject (hdc, hbrush );
SelectObject (hdc, hpen );
Pie (hdc, cx-r + 19, cy-r + 19, cx + r-19, cy + r-19, cx + r-19, cy, cx + r-19, cy );
MoveToEx (hdc, cx, cy, NULL );

DeleteObject (hbrush );
DeleteObject (hpen );

// Obtain the local time
GetLocalTime (& amp; m );
// Seconds
Hpen = CreatePen (PS_SOLID, 2, RGB (0, 0, 255 ));
SelectObject (hdc, hpen );
MoveToEx (hdc, cx, cy, NULL );
LineTo (hdc, (int) (cx + (R-20) * sin (small M. wSecond * PI/30), (int) (cy-(R-20) * cos (cost M. wSecond * PI/30 )));
DeleteObject (hpen );

// Draw the sub-needle
Hpen = CreatePen (PS_SOLID, 4, RGB (0,255, 0 ));
SelectObject (hdc, hpen );
MoveToEx (hdc, cx, cy, NULL );
LineTo (hdc, (int) (cx + (r-50) * sin (small M. wMinute * PI/30), (int) (cy-(r-50) * cos (cost M. wMinute * PI/30 )));
DeleteObject (hpen );

// Draw the hour hand

Hpen = CreatePen (PS_SOLID, 8, RGB (255, 0 ));
SelectObject (hdc, hpen );
MoveToEx (hdc, cx, cy, NULL );
LineTo (hdc, (int) (cx + (r-100) * sin (small M. wHour % 12 * PI/6), (int) (cy-(r-100) * cos (Bytes M. wHour % 12 * PI/6 )));
Deleteobject (Hpen );

Endpaint (_ hwnd, & PS );

Return 0;
Case wm_timer:
Invalidaterect (_ hwnd, null, null); // when the timer arrives, refresh the invalid Zone
Return 0;
Case wm_destroy:
Postquitmessage (0 );
Return 0;
}

Return defwindowproc (_ hwnd, _ message, _ wparam, _ lparasm );

}