Getting Started > For Beginners > Implementing Scrollbars > Implementing Scrollbars: Step 8

Implementing Scrollbars: Step 8

In the Window_OnPaint function, change the WM_PAINT message handling code.

VOID Window_OnPaint (HWND hWnd) 
{ 
   HDC hdc; 
   PAINTSTRUCT ps; 
   HPALETTE hOldPal = NULL; 
   hdc = BeginPaint (hWnd, &ps);/* Get DC */ 
   if (Data.BitmapHandle.Flags.Allocated) /* Do we have an image? */ 
   { 
      if (Data.hPalette)        /* Is there a palette that needs to be 
         selected? */ 
      hOldPal = SelectPalette (hdc, Data.hPalette, TRUE);  /* Select it. */ 
      /* Paint it */ 
      L_PaintDC (hdc, 
      &Data.BitmapHandle, 
      &rLeadSource, 
      NULL, 
      &rLeadDest, 
      &ps.rcPaint, 
      SRCCOPY); 
      if (Data.hPalette)        /* Return old palette if there is one. */ 
         SelectPalette (hdc, hOldPal, TRUE); 
      if (bFirst) 
      { 
         bFirst = FALSE; 
         /* Reset the counter and start a timer to be used for display delay. */ 
         nCount = 0; 
         nTimer = SetTimer (hWnd, 1, 1000, NULL); 
         if (!nTimer) 
         { 
            MessageBox (hWnd, TEXT("No Timers Are Available!"), 
            TEXT("ERROR - Resources"), MB_OK); 
            /* No timers are available, so quit the application. */ 
            FORWARD_WM_DESTROY (hWnd, PostMessage); 
         } 
      } 
   } 
   EndPaint (hWnd, &ps);        /* Return DC */ 
   return; 
}