IsGUIThread function (winuser.h)

Determines whether the calling thread is already a GUI thread. It can also optionally convert the thread to a GUI thread.

Syntax

BOOL IsGUIThread(
  [in] BOOL bConvert
);

Parameters

[in] bConvert

Type: BOOL

If TRUE and the thread is not a GUI thread, convert the thread to a GUI thread.

Return value

Type: BOOL

The function returns a nonzero value in the following situations:

• If the calling thread is already a GUI thread.
• If bConvert is TRUE and the function successfully converts the thread to a GUI thread.

If bConvert is TRUE and the function cannot successfully convert the thread to a GUI thread, IsGUIThread returns ERROR_NOT_ENOUGH_MEMORY.

Requirements

See also

Windows Overview