AccessibleObjectFromWindow

The AccessibleObjectFromWindow function retrieves the address of the specified interface to the object associated with the given window.

For more information about COM parameter attributes, allocating memory, and freeing memory, see Definitions of Parameter Attributes.

STDAPI AccessibleObjectFromWindow(
HWNDhwnd,DWORDdwObjectID,REFIIDriid,void** ppvObject);

Parameters

• hwnd
  [in] Specifies the handle of a window for which an object is to be retrieved. To retrieve an interface pointer to the cursor or caret object, specify NULL and use the appropriate object ID in dwObjectID.
• dwObjectID
  [in] Specifies the object ID. This value is one of the standard object identifier constants or a custom object ID such as OBJID_NATIVEOM, which is the object ID for the Microsoft Office native object model. For more information about OBJID_NATIVEOM, see the Remarks section in this topic.
• riid
  [in] Specifies the reference identifier of the requested interface. This value is either IID_IAccessible or IID_IDispatch.
• ppvObject
  [out] Address of a pointer variable that receives the address of the specified interface.

Return Values

If successful, returns S_OK.

If not successful, returns one of the following or another standard COM error code.

Error	Description
E_INVALIDARG	An argument is invalid.
E_NOINTERFACE	The requested interface is not supported.

Remarks

Clients call this function to retrieve the address of an object's IAccessible, IDispatch, IEnumVARIANT, IUnknown, or other supported interface pointer.

As with other IAccessible methods and functions, clients might receive errors for IAccessible interface pointers because of a user action. For more information, see Receiving Errors for IAccessible Interface Pointers.

Clients use this function to obtain access to the Microsoft Office 2000 native object model. The native object model provides clients with accessibility information about an Office application's document or client area that is not exposed by Active Accessibility.

To obtain an IDispatch interface pointer to a class supported by the native object model, specify OBJID_NATIVEOM in dwObjectID. When using this object identifier, the hwnd parameter must match the following window class types.

Office application	Window class	IDispatch pointer to
Word	_WwG	Window
Excel	EXCEL7	Window
PowerPoint	paneClassDC	DocumentWindow
Command Bars	MsoCommandBar	CommandBar

Note that the above window classes correspond to the innermost document window or pane window. For more information about the Office object model, see the Microsoft Office/Visual Basic Programmer's Guide.

Requirements

**  Windows NT/2000/XP/Server 2003:** Included in Windows 2000 and later.
**  Windows 95/98/Me:** Included in Windows 98 and later.
**  Redistributable:** Requires Active Accessibility 1.3 RDK on Windows NT 4.0 SP6 and Windows 95.
**  Header:** Declared in Oleacc.h.
**  Library:** Use Oleacc.lib.

See Also

IAccessible, AccessibleObjectFromEvent, AccessibleObjectFromPoint, IDispatch Interface