Create a location message

OIMMessageInfo *message =
    [OIMMessageInfo createLocationMessage:@"Pudong, Shanghai"
                                  latitude:31.2304
                                 longitude:121.4737];

The arguments are the location description, latitude, and longitude. Coordinates come from a location result obtained by the application or a location selected by the user, and both sides should use the same coordinate system. This selector only creates an object to be sent; it does not obtain location data or correct coordinates.