Oh, CORRECT! It stops complaining and begins to work as we expect when I put the message into a separate package. Thank you, Ken. Hao On Tue, Jun 8, 2010 at 4:22 PM, Ken Conley wrote: > As a follow-up, if you're trying to hack rviz by adding new messages to it, > you need to add the messages in a separate package. rviz builds its own > swig-based Python module that prevents the ROS python data classes from > loading. C++ messages will work, but Python will not due to the way Python > defines modules. > >  - Ken > > On Tue, Jun 8, 2010 at 4:05 PM, Ken Conley wrote: >> >> Hi Hao, >> >> I'm not sure what you mean by "rostopic echo *" >> >> Your error message is odd because there is no such message >> "rviz/SelectionMessage". It would be helpful if you provided more details. >> >>  - Ken >> >> On Tue, Jun 8, 2010 at 3:54 PM, Hao Dang wrote: >>> >>> Hello all, >>> >>> I met a problem when I use "rostopic echo *" on a topic which I built, >>> ROS complained and said "Cannot load message class for >>> [rviz/SelectionMessage]. Are your messages built?".  But when I wrote >>> a dedicated listener which subscribed to this topic, I can get the >>> information of the published messages to this topic.  Does anybody >>> know why?  By the way, "rostopic list" can list the topic and >>> "rostopic info" can also get the information of the topic. >>> >>> Thank you! >>> >>> Hao >>> _______________________________________________ >>> ros-users mailing list >>> ros-users@code.ros.org >>> https://code.ros.org/mailman/listinfo/ros-users >> > > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > >