Using SS_BITMAP style on static control in a dialog frame - c++

Question

I am attempting to write a slot machine Win32 App that uses images to display the result of the spins. I know how to display an image on a normal LRESULT CALLBACK frame, but i'm lost when it comes to displaying images on a dialog. Could anyone help me by explaining(in-depth) how i would go about displaying images? I really appreciate it.
My current Dialog callback:
BOOL CALLBACK DlgProc(HWND hwnd, UINT message,WPARAM wParam, LPARAM lParam)
{
switch(message)
{
case WM_INITDIALOG: //dialog created
g_hbmObject = LoadBitmap(GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_OBJECT));
//initialize slotmachine class
Machine.Initialize(time(0));
if(g_hbmObject == NULL) //test if object is loaded correctly
std::cerr << "Could not load ball..";
break;
case WM_COMMAND: //switch command
switch(LOWORD(wParam))
{
case IDC_SPIN: //slot machine spins
//put spin function, decide what to display
//do i put the display image command here? or where?
break;
case IDC_EXIT: //exit button
DeleteObject(g_hbmObject);
EndDialog(hwnd, 0);
break;
}
break;
case WM_CLOSE:
case WM_DESTROY: //case program is exited
DeleteObject(g_hbmObject);
PostQuitMessage(0);
break;
default:
return FALSE;
}
return TRUE;
}

Answer 1

The following code registers a "REEL" window class: a control that displays a spinning reel for a slot machine. You can create multiple instances of it on a dialog using resource statements like:
CONTROL "",IDC_REEL1,"REEL",0,14,50,40,40
CONTROL "",IDC_REEL2,"REEL",0,70,50,40,40
The reel spins endlessly, but you can easily add private messages to start and stop it.
As explained in the comments, it expects a bitmap representing a reel with resource ID IDB_REEL.
HBITMAP g_hbmpReel;
LRESULT CALLBACK ReelWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
const int ReelTimerId = 5;
switch (message)
{
case WM_CREATE:
SetTimer(hWnd, ReelTimerId, 10, 0);
break;
case WM_DESTROY:
KillTimer(hWnd, ReelTimerId);
break;
case WM_SIZE:
SetWindowPos(hWnd, 0, 0, 0, 40, 40, SWP_NOACTIVATE | SWP_NOMOVE | SWP_NOREDRAW | SWP_NOZORDER);
break;
case WM_TIMER:
if (wParam == ReelTimerId)
{
int offset = GetWindowLong(hWnd, 0);
offset = (offset + 5) % 120;
SetWindowLong(hWnd, 0, offset);
InvalidateRect(hWnd, 0, FALSE);
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
HDC hdcReel = CreateCompatibleDC(hdc);
HBITMAP hbmpOld = (HBITMAP)SelectObject(hdcReel, g_hbmpReel);
int offset = GetWindowLong(hWnd, 0);
BitBlt(hdc, 0, 0, 40, 40, hdcReel, 0, offset, SRCCOPY);
SelectObject(hdcReel, hbmpOld);
DeleteDC(hdcReel);
EndPaint(hWnd, &ps);
}
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
ATOM RegisterReel(HINSTANCE hInstance)
{
WNDCLASSEX wcex = {0};
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.lpfnWndProc = ReelWndProc;
// Window data used to hold the position of the reel
wcex.cbWndExtra = sizeof(int);
wcex.hInstance = hInstance;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszClassName = L"REEL";
// IDB_REEL is a 40x160 bitmap representing a reel with THREE 40x40 symbols.
// The bottom 40x40 square should be the same as the topmost.
g_hbmpReel = LoadBitmap(hInstance, MAKEINTRESOURCE(IDB_REEL));
return RegisterClassEx(&wcex);
}