IsGUIThread function

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

Syntax

BOOL IsGUIThread(
  BOOL bConvert
);

Parameters

bConvert

Type: BOOL

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

Return Value

Type: 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.
Otherwise, the function returns zero.

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

Requirements

   
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header winuser.h (include Windows.h)
Library User32.lib
DLL User32.dll

See Also

Windows Overview