Question

WIN32编程中，怎么实现窗口的滚动条功能

Answer 1

windows程序设计中的代码:
case   WM_CREATE :
        
                  hInstance = (HINSTANCE) GetWindowLong (hwnd, GWL_HINSTANCE) ;
        
       
        
                          // Create the white-rectangle window against which the
        
                          // scroll bars will be positioned. The child window ID is 9.
        
        
        
                  hwndRect = CreateWindow (TEXT ("static"), NULL,
        
                       WS_CHILD | WS_VISIBLE | SS_WHITERECT,
        
                       0, 0, 0, 0,
        
                       hwnd, (HMENU) 9, hInstance, NULL) ;
        
        
        
                  for (i = 0 ; i < 3 ; i++)
        
                  {
        
                                  // The three scroll bars have IDs 0, 1, and 2, with
        
                                  // scroll bar ranges from 0 through 255.
        
             
        
                  hwndScroll[i] = CreateWindow (TEXT ("scrollbar"), NULL,
        
                               WS_CHILD | WS_VISIBLE |
        
                               WS_TABSTOP | SBS_VERT,
        
                                  0, 0, 0, 0,
        
               hwnd, (HMENU) i, hInstance, NULL) ;
        
             
        
                          SetScrollRange (hwndScroll[i], SB_CTL, 0, 255, FALSE) ;
        
                          SetScrollPos   (hwndScroll[i], SB_CTL, 0, FALSE) ;
        
             
        
      // The three color-name labels have IDs 3, 4, and 5,
        
     // and text strings "Red", "Green", and "Blue".
        
             
        
           hwndLabel [i] = CreateWindow (TEXT ("static"), zColorLabel[i],
        
                                   WS_CHILD | WS_VISIBLE | SS_CENTER,
        
                                     0, 0, 0, 0,
        
                                     hwnd, (HMENU) (i + 3),
        
                                     hInstance, NULL) ;
        
             
        
                          // The three color-value text fields have IDs 6, 7,
        
                          // and 8, and initial text strings of "0".
        
             
        
hwndValue [i] = CreateWindow (TEXT ("static"), TEXT ("0"),
        
                                WS_CHILD | WS_VISIBLE | SS_CENTER,
        
                                0, 0, 0, 0,
        
                               hwnd, (HMENU) (i + 6),
        
                                hInstance, NULL) ;
        
             
        
                          OldScroll[i] = (WNDPROC) SetWindowLong (hwndScroll[i],
        
                                 GWL_WNDPROC, (LONG) ScrollProc) ;
        
             
        
                          hBrush[i] = CreateSolidBrush (crPrim[i]) ;
        
                  }
        
        
        
                    hBrushStatic = CreateSolidBrush (
        
                                GetSysColor (COLOR_BTNHIGHLIGHT)) ;
        
        
        
            cyChar = HIWORD (GetDialogBaseUnits ()) ;
        
           return 0 ;
        
        
        
           case   WM_SIZE :
        
                  cxClient = LOWORD (lParam) ;
        
                  cyClient = HIWORD (lParam) ;
        
                  SetRect (&rcColor, cxClient / 2, 0, cxClient, cyClient) ;
        
        
        
                  MoveWindow (hwndRect, 0, 0, cxClient / 2, cyClient, TRUE) ;
        
        
        
                  for (i = 0 ; i < 3 ; i++)
        
           {
        
                         MoveWindow (hwndScroll[i],
        
                                 (2 * i + 1) * cxClient / 14, 2 * cyChar,
        
                                  cxClient / 14, cyClient - 4 * cyChar, TRUE) ;
        
             
        
                          MoveWindow (hwndLabel[i],
        
                                  (4 * i + 1) * cxClient / 28, cyChar / 2,
        
                                 cxClient / 7, cyChar, TRUE)
        
             
        
                          MoveWindow (hwndValue[i],
        
                                  (4 * i + 1) * cxClient / 28,
        
                                  cyClient - 3 * cyChar / 2,
        
                                  cxClient / 7, cyChar, TRUE) ;
        
           }
        
                  SetFocus (hwnd) ;
        
                  return 0 ;
        
        
        
           case   WM_SETFOCUS :
        
                  SetFocus (hwndScroll[idFocus]) ;
        
                  return 0 ;
        
        
        
           case   WM_VSCROLL :
        
                 i = GetWindowLong ((HWND) lParam, GWL_ID) ;
        
        
        
                  switch (LOWORD (wParam))
        
                  {
        
                  case   SB_PAGEDOWN :
        
                                         color[i] += 15 ;
        
                           // fall through
        
                  case   SB_LINEDOWN :
        
                                       color[i] = min (255, color[i] + 1) ;
        
                                         break ;
        
             
        
                  case   SB_PAGEUP :
        
                                         color[i] -= 15 ;
        
                           // fall through
        
                  case   SB_LINEUP :
        
                                         color[i] = max (0, color[i] - 1) ;
        
                                         break ;
        
             
        
                  case   SB_TOP :
        
                                         color[i] = 0 ;
        
                                         break ;
        
             
        
                  case   SB_BOTTOM :
        
                                         color[i] = 255 ;
        
                                         break ;
        
             
        
                  case   SB_THUMBPOSITION :
        
                  case   SB_THUMBTRACK :
        
                                         color[i] = HIWORD (wParam) ;
        
                                         break ;
        
             
        
                  default :
        
                                         break ;
        
                  }
        
                 SetScrollPos  (hwndScroll[i], SB_CTL, color[i], TRUE) ;
        
                  wsprintf (szBuffer, TEXT ("%i"), color[i]) ;
        
                  SetWindowText (hwndValue[i], szBuffer) ;
        
        
        
                  DeleteObject ((HBRUSH)
        
                                  SetClassLong (hwnd, GCL_HBRBACKGROUND, (LONG)
        
                  CreateSolidBrush (RGB (color[0], color[1], color[2])))) ;
        
        
        
                  InvalidateRect (hwnd, &rcColor, TRUE) ;
        
                 return 0 ;