ShellProc
The ShellProc
hook procedure is an application-defined or library-defined callback function a
shell application uses to receive useful notifications from the system.
LRESULT CALLBACK ShellProc(
|
int nCode, |
// hook code |
|
WPARAM wParam, |
// event-specific
information |
|
LPARAM lParam |
// event-specific
information |
|
); |
|
Parameters
nCode
Specifies the
hook code. This parameter can be one of the following values:
|
Value |
Meaning |
|
HSHELL_ACTIVATESHELLWINDOW |
The shell
should activate its main window. |
|
HSHELL_GETMINRECT |
Windows
95 only: A window is being
minimized or maximized and the system needs the coordinates of the minimized
rectangle for the window. The wParam parameter contains the handle of
the window, and the lParam parameter contains the address of a RECT structure that receives
the coordinates. |
|
HSHELL_LANGUAGE |
Windows
95 only: Keyboard language was
changed or a new keyboard layout was loaded. |
|
HSHELL_REDRAW |
Windows
95 only: The title of a window in
the task bar has been redrawn. The wParam parameter contains the
handle of the window. |
|
HSHELL_TASKMAN |
Windows
95 only: The user has selected the
task list. The wParam parameter is undefined and should be ignored. A
shell application that provides a task list should return TRUE to prevent
Windows from starting its task list. |
|
HSHELL_WINDOWACTIVATED |
Windows
95 only: The activation has changed
to a different top-level, unowned window. The wParam parameter
contains the handle of the window. |
|
HSHELL_WINDOWCREATED |
A
top-level, unowned window has been created. The window exists when the system
calls a ShellProc function. |
|
HSHELL_WINDOWDESTROYED |
A
top-level, unowned window is about to be destroyed. The window still exists
when the system calls a ShellProc function. |
If nCode
is less than zero, the hook procedure must pass the message to the CallNextHookEx function without further
processing and should return the value returned by CallNextHookEx.
wParam
Specifies
additional information the shell application may require. If the nCode
parameter is HSHELL_ACTIVATESHELLWINDOW, the wParam parameter is not
used. If nCode is HSHELL_WINDOWCREATED or HSHELL_WINDOWDESTROYED, wParam
specifies the handle of the window being created or destroyed, respectively.
lParam
Windows
95:
Specifies
additional information. The exact value depends on the value of the nCode
parameter. If nCode is HSHELL_GETMINRECT, lParam is LPRECT. If nCode
is HSHELL_WINDOWSACTIVATED, lParam is fFullScreen. If nCode
is HSHELL_REDRAW, lParam is fNewFlash.
Windows
NT:
This
parameter must be zero.
Return Values
The return
value should be zero.
Remarks
An
application installs the hook procedure by specifying the WH_SHELL hook type
and the address of the hook procedure in a call to the SetWindowsHookEx
function.
ShellProc is a placeholder for the application-defined or
library-defined function name.
See Also