UnhookWindowsHookEx function (winuser.h)

Article
02/22/2024

Removes a hook procedure installed in a hook chain by the SetWindowsHookEx function.

Syntax

BOOL UnhookWindowsHookEx(
  [in] HHOOK hhk
);

Parameters

[in] hhk

Type: HHOOK

A handle to the hook to be removed. This parameter is a hook handle obtained by a previous call to SetWindowsHookEx.

Return value

Type: BOOL

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The hook procedure can be in the state of being called by another thread even after UnhookWindowsHookEx returns. If the hook procedure is not being called concurrently, the hook procedure is removed immediately before UnhookWindowsHookEx returns.

Examples

For an example, see Monitoring System Events.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	winuser.h (include Windows.h)
Library	User32.lib
DLL	User32.dll
API set	ext-ms-win-ntuser-window-l1-1-0 (introduced in Windows 8)