UnhookWindowsHookEx

The UnhookWindowsHookEx function removes a hook procedure installed in a hook chain by the SetWindowsHookEx function.

BOOL UnhookWindowsHookEx(
  HHOOK hhk   // handle to hook procedure to remove
);
 

Parameters

hhk

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

Return Values

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.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in winuser.h.
  Import Library: Use user32.lib.

See Also

Hooks Overview, Hook Functions, SetWindowsHookEx, UnhookWindowsHook