The WM_SETFOCUS message is sent to a window after it has gained the keyboard focus.
WM_SETFOCUS
hwndLoseFocus = (HWND) wParam; // handle of window losing focus
Parameters
hwndLoseFocus
Value of wParam. Identifies the window that has lost the keyboard focus (may be NULL).
Return Values
An application should return zero if it processes this message.
Remarks
To display a caret, an application should call the appropriate caret functions when it receives the WM_SETFOCUS message.
See Also