Windows程序设计 滚动条

第九章 滚动条 P306

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/*----------------------------------------   COLORS1.C -- Colors Using Scroll Bars                (c) Charles Petzold, 1998  ----------------------------------------*/#include <windows.h>LRESULT CALLBACK WndProc    (HWND, UINT, WPARAM, LPARAM) ;LRESULT CALLBACK ScrollProc (HWND, UINT, WPARAM, LPARAM) ;int     idFocus ;WNDPROC OldScroll[3] ;int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,                    PSTR szCmdLine, int iCmdShow){     static TCHAR szAppName[] = TEXT ("Colors1") ;     HWND         hwnd ;     MSG          msg ;     WNDCLASS     wndclass ;          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 = CreateSolidBrush (0) ;     wndclass.lpszMenuName  = NULL ;     wndclass.lpszClassName = szAppName ;          if (!RegisterClass (&wndclass))     {          MessageBox (NULL, TEXT ("This program requires Windows NT!"),                      szAppName, MB_ICONERROR) ;          return 0 ;     }     hwnd = CreateWindow (szAppName, TEXT ("Color Scroll"),                          WS_OVERLAPPEDWINDOW,                          CW_USEDEFAULT, CW_USEDEFAULT,                          CW_USEDEFAULT, CW_USEDEFAULT,                          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 COLORREF crPrim[3] = { RGB (255, 0, 0), RGB (0, 255, 0),                                   RGB (0, 0, 255) } ;     static HBRUSH  hBrush[3], hBrushStatic ;     static HWND    hwndScroll[3], hwndLabel[3], hwndValue[3], hwndRect ;     static int     color[3], cyChar ;     static RECT    rcColor ;     static TCHAR * szColorLabel[] = { TEXT ("Red"), TEXT ("Green"),                                        TEXT ("Blue") } ;     HINSTANCE      hInstance ;     int            i, cxClient, cyClient ;     TCHAR          szBuffer[10] ;          switch (message)     {     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"), szColorLabel[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 ;               case WM_CTLCOLORSCROLLBAR :          i = GetWindowLong ((HWND) lParam, GWL_ID) ;          return (LRESULT) hBrush[i] ;                    case WM_CTLCOLORSTATIC :          i = GetWindowLong ((HWND) lParam, GWL_ID) ;                         if (i >= 3 && i <= 8)    // static text controls          {               SetTextColor ((HDC) wParam, crPrim[i % 3]) ;               SetBkColor ((HDC) wParam, GetSysColor (COLOR_BTNHIGHLIGHT));               return (LRESULT) hBrushStatic ;          }          break ;                    case WM_SYSCOLORCHANGE :          DeleteObject (hBrushStatic) ;          hBrushStatic = CreateSolidBrush (GetSysColor (COLOR_BTNHIGHLIGHT)) ;          return 0 ;     case WM_DESTROY :          DeleteObject ((HBRUSH)               SetClassLong (hwnd, GCL_HBRBACKGROUND, (LONG)                     GetStockObject (WHITE_BRUSH))) ;                         for (i = 0 ; i < 3 ; i++)               DeleteObject (hBrush[i]) ;                         DeleteObject (hBrushStatic) ;          PostQuitMessage (0) ;          return 0 ;     }     return DefWindowProc (hwnd, message, wParam, lParam) ;}     LRESULT CALLBACK ScrollProc (HWND hwnd, UINT message,                              WPARAM wParam, LPARAM lParam){     int id = GetWindowLong (hwnd, GWL_ID) ;               switch (message)     {     case WM_KEYDOWN :          if (wParam == VK_TAB)               SetFocus (GetDlgItem (GetParent (hwnd),                     (id + (GetKeyState (VK_SHIFT) < 0 ? 2 : 1)) % 3)) ;          break ;                    case WM_SETFOCUS :          idFocus = id ;          break ;     }     return CallWindowProc (OldScroll[id], hwnd, message, wParam, lParam) ;}

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