Can't input Chinese with ibus

    newly installed Fedora 31 x86_64 with ibus, online installed Qt 5.13.2 with opensource "qt-unified-linux-x64-3.1.1-online.run", and qt creator ver is 4.10.2,  I can't input Chinese in the qt creator editor.  I've installed ibus-devel, ibus-qt, and the env GTK_IM_MODULE=ibus, QT_IM_MODULE=ibus, XMODIFIERS=@im=ibus.  even if I compile the platforminputcontexts from the 5.13.2 Src's plugins and replace the libcomposeplatforminputcontextplugin.so and libibusplatforminputcontextplugin.so... still can't input Chinese! while I can currectly input Chinese in firefox, chrome, gedit... or terminal