I check the source and I found:
in src/xfns.c: create_frame_xic()
xic = XCreateIC (xim,
               XNInputStyle, xic_style,
               XNClientWindow, FRAME_X_WINDOW (f),
               XNFocusWindow, FRAME_X_WINDOW (f),
               XNStatusAttributes, status_attr,
               XNPreeditAttributes, preedit_attr,
               NULL);
When the locale (LC_ALL)is en_US.utf8, the return value of XCreatIC is NULL.
When set the locale to zh_CN.utf8 , the return value of XCreateIC is OK, and
SCIM or IBUS works fine.

I don't know why.



On Sat, Sep 4, 2010 at 9:14 PM, Štěpán Němec <stepnem@gmail.com> wrote:

> "Shaowei Wang (wsw)" <wsw1wsw2@gmail.com> writes:
>
> > Hi all
> >   I want to use xim program(scim) with emacs and I have some issues here.
> >
> > My scim works find with gtk programs and other X programs(rxvt-unicode)
> but
> > emacs. I found the locale is the
> > key point.
>
> [...]
>
> > I did lots of google searchs. Some guy said it is the Xorg problem and
> > others said it's the font (may be font path) problem.
> > But how do we explane that other X program works fine with scim?
>
> I'll let others do the explaining, but rest assured that getting GUI
> Emacs to work with SCIM or IBus is non-trivial. AFAIK you need
> third-party packages for that, specifically for SCIM I used to use this
> (now I'm using the IBus interface by the same author):
>
> http://www.emacswiki.org/emacs/ScimBridge
>
> [Also note that this is emacs-devel; questions of this sort are better
> served on help-gnu-emacs@gnu.org or other help fora.]
>
> Štěpán
>