publisher how to sent two or more topics to the subscriber?

[zixuan-su]

hi, i am a freshman ,i learn fastdds for three days , i have passed that publisher sent one topic to the subscriber ,but when i want to try more, i failed, publisher can sent two topic, but subscriber only can receive a topic ,could you please give me some examples?
thanks.... i have searched many reference , but cant to answer my question.

[EduPonz]

This is a duplicate of #2663. There, it is explained that to received data in two different topics, you'd need two different data readers (one on each topic). It is also explained how to get the data on the subscriber callbacks instead of the data readers'.

[zixuan-su]

thanks! i have seen it , now i am looking up how to use subscriber callbacks to receive two topics.
In "HelloWorld" example, it uses the function "void on_data_available(DataReader* reader)", I would instead of "on_data_on_readers() "?
Sorry, I am very confused, I want to search some codes, ..I will make more effort to try.
Thank you again for your help.

[EduPonz]

When creating a Subscriber, you can pass a SubscriberListener to it. As explained in Listener, SubscriberListener inherits from DataReaderListener. Mind that when setting a SubscriberListener, on_data_on_readers will be called unless otherwise specified in the mask. That means that on_data_available will not be called in that case.

[zixuan-su]

I'll take a closer look at your example, thanks for your reply!!!

[zixuan-su]

hi,Can you help check my code?Pub
Sub
i.............

[EduPonz]

Hi @zixuan-su ,

Unfortunately I don't have time at the moment to review your code. You could try to reach [email protected] to get some commercial support on the matter.