Wm_drawitem

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?

Code:

#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) ; }