FMExtensionProc callback function

Specifies an application-defined callback function called by File Manager to communicate with a File Manager extension.

Syntax

LONG CALLBACK FMExtensionProc(
   HWND hwnd,
   WORD wMsg,
   LONG lParam
);

Parameters

hwnd

Type: HWND

A window handle to File Manager. An extension uses this handle to specify the parent window for any dialog box or message box it must display, and to send query messages to File Manager.

wMsg

Type: WORD

One of the following File Manager messages.

1 through 99

User selected an item from the extension-supplied menu. The value is the identifier of the selected menu item.

FMEVENT_HELPMENUITEM

User pressed F1 while selecting an extension menu or toolbar command item. Indicates that the extension should call WinHelp appropriately for the command item.

FMEVENT_HELPSTRING

User selected an extension menu or toolbar command item. Indicates that the extension should supply a Help string.

FMEVENT_INITMENU

User selected the extension's menu. The extension should initialize items in the menu.

FMEVENT_LOAD

File Manager is loading the extension DLL and prompts the DLL for information about the menu that the DLL supplies.

FMEVENT_SELCHANGE

Selection in the File Manager directory window or Search Results window has changed.

FMEVENT_TOOLBARLOAD

File Manager is creating the toolbar and prompts the extension DLL for information about any buttons the DLL adds to the toolbar.

FMEVENT_UNLOAD

File Manager is unloading the extension DLL.

FMEVENT_USER_REFRESH

User selected the Refresh command from the Window menu. The extension should update items in the menu, if necessary.

lParam

Type: LONG

Message-specific value.

Return value

Type: LONG

Returns a value dependent upon the wMsg parameter message.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Wfext.h
Unicode and ANSI names	FMExtensionProcW (Unicode)