the data representation of datareader and datawriter.

[wpengfei28]

When using CycloneDDS and Fast DDS for interoperability, CycloneDDS is the publisher and Fast DDS is the subscriber. The IDL uses @appendable, so the CycloneDDS publisher defaults to XCDR2, which causes QoS incompatibility with the Fast DDS subscriber and prevents them from matching.

When I use the Fast DDS HelloWorld example, I set the writer QoS to XCDR2:

writer_qos.representation().m_value.push_back(
eprosima::fastdds::dds::DataRepresentationId_t::XCDR2_DATA_REPRESENTATION
);
writer_ = publisher_->create_datawriter(topic_, writer_qos, this, StatusMask::all());

However, the Fast DDS ./build/hello_world publisher and ./build/hello_world subscriber still cannot match.

My question is: how can I make the Fast DDS subscriber match and receive data from a publisher using XCDR2, or how can I configure the Fast DDS subscriber to use XCDR2 encoding?