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 WNDCLASSEX

typedef struct {
    UINT cbSize;
    UINT style;
    WNDPROC lpfnWndProc;
    int cbClsExtra;
    int cbWndExtra;
    HINSTANCE hInstance;
    HICON hIcon;
    HCURSOR hCursor;
    HBRUSH hbrBackground;
    LPCTSTR lpszMenuName;
    LPCTSTR lpszClassName;
    HICON hIconSm;
} WNDCLASSEX, *PWNDCLASSEX;

Members

cbSize

Specifies the size, in bytes, of this structure. Set this member to sizeof(WNDCLASSEX). Be sure to set this member before calling the GetClassInfoEx function.

style

Specifies the class style(s). This member can be any combination of the Class Styles.

lpfnWndProc

Pointer to the window procedure. You must use the CallWindowProc function to call the window procedure. For more information, see WindowProc.

cbClsExtra

Specifies the number of extra bytes to allocate following the window-class structure. The system initializes the bytes to zero.

cbWndExtra

Specifies the number of extra bytes to allocate following the window instance. The system initializes the bytes to zero. If an application uses WNDCLASSEX to register a dialog box created by using the CLASS directive in the resource file, it must set this member to DLGWINDOWEXTRA.

hInstance

Handle to the instance that contains the window procedure for the class.

hIcon

Handle to the class icon. This member must be a handle to an icon resource. If this member is NULL, the system provides a default icon.

hCursor

Handle to the class cursor. This member must be a handle to a cursor resource. If this member is NULL, an application must explicitly set the cursor shape whenever the mouse moves into the application's window.

hbrBackground

Handle to the class background brush. This member can be a handle to the physical brush to be used for painting the background, or it can be a color value. A color value must be one of the following standard system colors (the value 1 must be added to the chosen color). If a color value is given, you must convert it to one of the following HBRUSH types:
• COLOR_ACTIVEBORDER
• COLOR_ACTIVECAPTION
• COLOR_APPWORKSPACE
• COLOR_BACKGROUND
• COLOR_BTNFACE
• COLOR_BTNSHADOW
• COLOR_BTNTEXT
• COLOR_CAPTIONTEXT
• COLOR_GRAYTEXT
• COLOR_HIGHLIGHT
• COLOR_HIGHLIGHTTEXT
• COLOR_INACTIVEBORDER
• COLOR_INACTIVECAPTION
• COLOR_MENU
• COLOR_MENUTEXT
• COLOR_SCROLLBAR
• COLOR_WINDOW
• COLOR_WINDOWFRAME
• COLOR_WINDOWTEXT The system automatically deletes class background brushes when the class is unregistered by using UnregisterClass. An application should not delete these brushes.

When this member is NULL, an application must paint its own background whenever it is requested to paint in its client area. To determine whether the background must be painted, an application can either process the WM_ERASEBKGND message or test the fErase member of the PAINTSTRUCT structure filled by the BeginPaint function.

lpszMenuName

Pointer to a null-terminated character string that specifies the resource name of the class menu, as the name appears in the resource file. If you use an integer to identify the menu, use the MAKEINTRESOURCE macro. If this member is NULL, windows belonging to this class have no default menu.

lpszClassName

Pointer to a null-terminated string or is an atom. If this parameter is an atom, it must be a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpszClassName; the high-order word must be zero. If lpszClassName is a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, or any of the predefined control-class names.

hIconSm

Handle to a small icon that is associated with the window class. If this member is NULL, the system searches the icon resource specified by the hIcon member for an icon of the appropriate size to use as the small icon.

Structure Information

Header Declared in Winuser.h, include Windows.h Minimum operating systems Windows 95, Windows NT 3.5 Unicode Implemented as ANSI and Unicode versions.

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time