about3.c

本书介绍了在Microsoft Windows 98、Microsoft Windows NT 4.0和Windows NT 5.0下程序写作的方法。这些程序用C语言编写并使用原始的Windows A

/*------------------------------------------
   ABOUT3.C -- About Box Demo Program No. 3
               (c) Charles Petzold, 1998
  ------------------------------------------*/

#include <windows.h>
#include "resource.h"

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
BOOL    CALLBACK AboutDlgProc (HWND, UINT, WPARAM, LPARAM) ;
LRESULT CALLBACK EllipPushWndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("About3") ;
     MSG          msg ;
     HWND         hwnd ;
     WNDCLASS     wndclass ;

     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (hInstance, szAppName) ;
     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 ;
     }
     
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = EllipPushWndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = NULL ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) (COLOR_BTNFACE + 1) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = TEXT ("EllipPush") ;

     RegisterClass (&wndclass) ;
     
     hwnd = CreateWindow (szAppName, TEXT ("About Box Demo Program"),
                          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 HINSTANCE hInstance ;
     
     switch (message)
     {
     case WM_CREATE :
          hInstance = ((LPCREATESTRUCT) lParam)->hInstance ;
          return 0 ;
          
     case WM_COMMAND :
          switch (LOWORD (wParam))
          {
          case IDM_APP_ABOUT :
               DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc) ;
               return 0 ;
          }
          break ;
          
     case WM_DESTROY :
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}

BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT message, 
                            WPARAM wParam, LPARAM lParam)
{
     switch (message)
     {
     case WM_INITDIALOG :
          return TRUE ;
          
     case WM_COMMAND :
          switch (LOWORD (wParam))
          {
          case IDOK :
               EndDialog (hDlg, 0) ;
               return TRUE ;
          }
          break ;
     }
     return FALSE ;
}

LRESULT CALLBACK EllipPushWndProc (HWND hwnd, UINT message, 
                                   WPARAM wParam, LPARAM lParam)
{
     TCHAR       szText[40] ;
     HBRUSH      hBrush ;
     HDC         hdc ;
     PAINTSTRUCT ps ;
     RECT        rect ;
     
     switch (message)
     {
     case WM_PAINT :
          GetClientRect (hwnd, &rect) ;
          GetWindowText (hwnd, szText, sizeof (szText)) ;
          
          hdc = BeginPaint (hwnd, &ps) ;
          
          hBrush = CreateSolidBrush (GetSysColor (COLOR_WINDOW)) ;
          hBrush = (HBRUSH) SelectObject (hdc, hBrush) ;
          SetBkColor (hdc, GetSysColor (COLOR_WINDOW)) ;
          SetTextColor (hdc, GetSysColor (COLOR_WINDOWTEXT)) ;
          
          Ellipse (hdc, rect.left, rect.top, rect.right, rect.bottom) ;
          DrawText (hdc, szText, -1, &rect,
                    DT_SINGLELINE | DT_CENTER | DT_VCENTER) ;
          
          DeleteObject (SelectObject (hdc, hBrush)) ;
          
          EndPaint (hwnd, &ps) ;
          return 0 ;
          
     case WM_KEYUP :
          if (wParam != VK_SPACE)
               break ;
                                             // fall through
     case WM_LBUTTONUP :
          SendMessage (GetParent (hwnd), WM_COMMAND,
               GetWindowLong (hwnd, GWL_ID), (LPARAM) hwnd) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}