APPLET_PROC callback function (cpl.h)

Serves as the entry point for a Control Panel application. This is a library-defined callback function.

APPLET_PROC AppletProc;

LONG AppletProc(
  HWND hwndCpl,
  UINT msg,
  LPARAM lParam1,
  LPARAM lParam2
)
{...}

hwndCpl

Type: HWND

The identifier of the main window of the controlling application. Use the hwndCPl parameter for dialog boxes or other windows that require a handle to a parent window.

msg

Type: UINT

The message being sent to the Control Panel application.

lParam1

Type: LPARAM

Additional message-specific information.

lParam2

Type: LPARAM

Additional message-specific information.

Type: LONG

The return value depends on the message.

For more information, see the descriptions of the individual Control Panel messages.

Implementers of Control Panel items must also implement this function. No default implementation is available.