Simple Types


This section contains information about the following simple types defined for use with Active Accessibility.

DDIHOOKPROC

The DDIHOOKPROC type defines a variable that points to a valid DDI hook callback procedure. The winddi.h header file uses the following definition.

typedef DWORD (CALLBACK* DDIHOOKPROC)(HDDI, LONG, DDITYPE, LPDDIPARAMS);

For more information, see DDIHookProc.

DDITYPE

The DDITYPE type defines a variable describing a specific DDI function call. The winddi.h header file uses the following definition.

typedef UINT    DDITYPE;

This data type is used with the CallNextDDI function and the DDIHookProc callback function.

HDDI

The HDDI type defines a 32-bit variable that identifies a DDI hook. The winddi.h header file uses the following definition.

typedef struct tagDDI FAR* HDDI;

This data type is used with the CallNextDDI, SetDDIHook, and UnhookDDIHook functions.

HWINEVENTHOOK

The HWINEVENTHOOK type defines a 32-bit variable that identifies a window event hook. The winable.h header file uses the following definition.

typedef DWORD HWINEVENTHOOK

This data type is used with the WinEventProc, SetWinEventHook, and UnhookWinEvent functions.

LPDDIPARAMS

The LPDDIPARAMS type defines a variable that contains the address of one of the DDI parameter structures. The DDI parameters structures are included in the winddi.h header file, which defines LPDDIPARAMS as follows:

typedef LPVOID  LPDDIPARAMS;

This data type is used with CallNextDDI function and the DDIHookProc callback function.

WINEVENTPROC

The WINEVENTPROC type defines a variable that conforms to the WinEventProc callback function declaration. The winable.h header file uses the following definition.

typedef VOID (CALLBACK* WINEVENTPROC)(
    HWINEVENTHOOK  hWinEventHook,
    DWORD          event,
    HWND           hwnd,
    LONG           idObject,
    LONG           idChild,
    DWORD          idEventThread,
    DWORD          dwmsEventTime);

For more information, see WinEventProc.

© 1997 Microsoft Corporation. All rights reserved. Legal Notices.