Export (0) Print
Expand All

SetFocus function

Sets the keyboard focus to the specified window. The window must be attached to the calling thread's message queue.

Syntax


HWND WINAPI SetFocus(
  _In_opt_  HWND hWnd
);

Parameters

hWnd [in, optional]

Type: HWND

A handle to the window that will receive the keyboard input. If this parameter is NULL, keystrokes are ignored.

Return value

Type: HWND

If the function succeeds, the return value is the handle to the window that previously had the keyboard focus. If the hWnd parameter is invalid or the window is not attached to the calling thread's message queue, the return value is NULL. To get extended error information, call GetLastError.

Remarks

The SetFocus function sends a WM_KILLFOCUS message to the window that loses the keyboard focus and a WM_SETFOCUS message to the window that receives the keyboard focus. It also activates either the window that receives the focus or the parent of the window that receives the focus.

If a window is active but does not have the focus, any key pressed will produce the WM_SYSCHAR, WM_SYSKEYDOWN, or WM_SYSKEYUP message. If the VK_MENU key is also pressed, the lParam parameter of the message will have bit 30 set. Otherwise, the messages produced do not have this bit set.

By using the AttachThreadInput function, a thread can attach its input processing to another thread. This allows a thread to call SetFocus to set the keyboard focus to a window attached to another thread's message queue.

Examples

For an example, see Initializing a Dialog Box.

Requirements

Minimum supported client

Windows 2000 Professional [desktop apps only]

Minimum supported server

Windows 2000 Server [desktop apps only]

Header

Winuser.h (include Windows.h)

Library

User32.lib

DLL

User32.dll

See also

Reference
GetFocus
WM_KILLFOCUS
WM_SETFOCUS
WM_SYSCHAR
WM_SYSKEYDOWN
WM_SYSKEYUP
Conceptual
Keyboard Input
Other Resources
AttachThreadInput

 

 

Community Additions

ADD
Show:
© 2014 Microsoft