| LRESULT CALLBACK ShellProc(code, wParam, lParam) | |||||
| int code; | /* process-message flag, */ | ||||
| WPARAM wParam; | /* current-task flag, */ | ||||
| LPARAM lParam; | /* undefined | */ | |||
The ShellProc function is a library-defined callback function that a shell application can use to receive useful notifications from the system.
code
Specifies a shell-notification code. This parameter can be one of the following values:
| Value | Meaning |
| HSHELL_ACTIVATESHELLWINDOW | The shell application should activate its main window. |
| HSHELL_WINDOWCREATED | A top-level, unowned window was 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. |
wParam
Specifies additional information the shell application may need. The interpretation of this parameter depends on the value of the code parameter, as follows:
| code | wParam |
| HSHELL_ACTIVATESHELLWINDOW | Not used. |
| HSHELL_WINDOWCREATED | Specifies the handle of the window being created. |
| HSHELL_WINDOWDESTROYED | Specifies the handle of the window being destroyed. |
lParam
Reserved; not used.
The return value should be zero.
An application must install this callback function by specifying the WH_SHELL filter type and the procedure-instance address of the callback function in a call to the SetWindowsHook function.
ShellProc is a placeholder for the library-defined function name. The actual name must be exported by including it in an EXPORTS statement in the library's module-definition file.