SUBCLASSPROC callback function (commctrl.h)

Defines the prototype for the callback function used by RemoveWindowSubclass and SetWindowSubclass.

Syntax

SUBCLASSPROC Subclassproc;

LRESULT Subclassproc(
  HWND hWnd,
  UINT uMsg,
  WPARAM wParam,
  LPARAM lParam,
  UINT_PTR uIdSubclass,
  DWORD_PTR dwRefData
)
{...}

Parameters

hWnd

Type: HWND

The handle to the subclassed window.

uMsg

Type: UINT

The message being passed.

wParam

Type: WPARAM

Additional message information. The contents of this parameter depend on the value of uMsg.

lParam

Type: LPARAM

Additional message information. The contents of this parameter depend on the value of uMsg.

uIdSubclass

Type: UINT_PTR

The subclass ID.

dwRefData

Type: DWORD_PTR

The reference data provided to the SetWindowSubclass function. This can be used to associate the subclass instance with a "this" pointer.

Return value

Type: LRESULT

The return value is the result of the message processing and depends on the message sent.

Requirements