It does not work this way. Unfortunately, your application lacked the documents to convince the visa officer about your purpose of visit. Business works differently in Canada (or even in the US and Europe) as compared to that in Asia
It would be a bit unrealistic to attend an exhibition and hope to start a business with a Canadian company right away.
Also, for your visa application, you had not demonstrated that you had considered other product brands/manufacturers in Europe.
1. Did your customer apply for a TRV as well?
2. Sometimes the customer would also want to meet potential Canadian companies. But, this does not seem to be the case.
3. As your customer knows the specific Canadian product/manufacturer to replace the Chinese products then your customer could consider interacting directly/purchasing these products directly from the Canadian company, right?
Hope you can see how this purpose of visit comes across from a visa perspective
