Wm_drawitem

[MasterDucky]

I'm writing a chessboard with GDI and when I click on a square the color changes to the opposite color but then it wont get redrawn again to normal.
I verified and I get only 5 WM_DRAWITEM message after I click a case instead of 64.

I wonder why?

#include <windows.h>
#include <iostream>
using namespace std;

#pragma comment(linker, "/subsystem:\"console\" /entry:\"WinMainCRTStartup\"")

#define ID_SQUARE_1      101
#define ID_SQUARE_2      102
#define SIZE     80
bool BlackOrWhite = 0;
int j=1, k=1, Ycoord=SIZE;
HINSTANCE hInst ;

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
void CheckClickedSquare(int wParam)
{
    switch (wParam)
    {
    case ID_SQUARE_1:
        //cout <<"1 work"<< endl;
        break ;
    case ID_SQUARE_2:
        //cout << "2 work" << endl;
        break ;
    }
}

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT ("GDI Chessboard") ;
    MSG          msg ;
    HWND         hwnd ;
    WNDCLASS     wndclass ;

    hInst = hInstance ;

    wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
    wndclass.lpfnWndProc   = WndProc ;
    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  = szAppName ;
    wndclass.lpszClassName = szAppName ;

    if (!RegisterClass (&wndclass))
    {
        MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                    szAppName, MB_ICONERROR) ;
        return 0 ;
    }

    hwnd = CreateWindow (szAppName, TEXT ("GDI Chessboard Demo"),
                         WS_OVERLAPPEDWINDOW,
                         CW_USEDEFAULT, CW_USEDEFAULT,
                         820, 800,
                         NULL, NULL, hInstance, NULL) ;

    ShowWindow (hwnd, iCmdShow) ;
    UpdateWindow (hwnd) ;

    while (GetMessage (&msg, NULL, 0, 0))
    {
        TranslateMessage (&msg) ;
        DispatchMessage (&msg) ;
    }
    return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static HWND h[64];
    static int       cxClient, cyClient, cxChar, cyChar ;
    int              cx, cy ;
    LPDRAWITEMSTRUCT pdis ;
    POINT            pt[3] ;
    RECT             rc ;
    PAINTSTRUCT ps;
    HDC hdc;
    int x = 116,y=100, number=0;
    char ch = 'A';
    char str[2], num[2];

    switch (message)
    {
    case WM_CREATE :
    cout << "WM_CREATE" << endl;
        cxChar = LOWORD (GetDialogBaseUnits ());
        cyChar = HIWORD (GetDialogBaseUnits ());

        for (int i=1; i<65; i++)
        {
            h[i] = CreateWindow (TEXT ("button"), TEXT (""),
                                 WS_CHILD | WS_VISIBLE | BS_OWNERDRAW,
                                 0, 0, SIZE, SIZE,
                                 hwnd, (HMENU)(i+100), 0, NULL);
        }
        return 0 ;

    case WM_SIZE :
    cout << "WM_SIZE" << endl;
 
        for (int i=1; i<65; i++)
        {
            if(i%8==1)
            {
                j=1;
                Ycoord += SIZE;
            }

            MoveWindow (h[i], j*SIZE, Ycoord-90, SIZE, SIZE, TRUE);
            j++;
         
        }
        return 0 ;

    case WM_DRAWITEM :
    cout << "WM_DRAWITEM" << endl;
        pdis = (LPDRAWITEMSTRUCT) lParam ;
        // Fill area with white and frame it black

        if(k++%8==1)
        {
            BlackOrWhite = !BlackOrWhite;
        }
        if(BlackOrWhite)
        {
            FillRect (pdis->hDC, &pdis->rcItem,
                      (HBRUSH) GetStockObject (WHITE_BRUSH)) ;
        }
        else
        {
            FillRect (pdis->hDC, &pdis->rcItem,
                      (HBRUSH) GetStockObject (BLACK_BRUSH)) ;
        }
        BlackOrWhite = !BlackOrWhite;

        FrameRect (pdis->hDC, &pdis->rcItem,
                   (HBRUSH) GetStockObject (BLACK_BRUSH)) ;

        return 0 ;

    case WM_PAINT:
    cout << "WM_PAINT" << endl;
        hdc = BeginPaint(hwnd, &ps);

        for (int i=1; i<9; i++)
        {
            sprintf(str,"%c", ch++);
            TextOut(hdc, x+((i-1)*(SIZE)), 40, str, 1);
            sprintf(num,"%i", i);
            TextOut(hdc, 60, y+((i-1)*(SIZE)), num, 1);
        }
        EndPaint(hwnd, &ps) ;
        return 0;

    case WM_COMMAND :
        cout << wParam << endl;
        CheckClickedSquare(wParam);
        return 0 ;

    case WM_DESTROY :
        PostQuitMessage (0) ;
        return 0 ;
    }
    return DefWindowProc (hwnd, message, wParam, lParam) ;
}