China already supplies JF-17s to Pakistan and therefore it wouldn't really make sense for Iran, a neighboring country with whom Pakistan has shaky relations at best, to also acquire the same jets. In theory its possible but not likely. I don't think Pakistan would be happy about it either.
Also according to most military experts, China is still 10 years behind Russia in aviation technology, specifically when it comes to jet engines. China has recently claimed that they are now no longer reliant on Russian engines for their J-20s but western experts are doubtful. At the same time, what China possesses is one thing, what it is willing to sell it Iran is quite another matter entirely.
When it comes to fighter jets Iranians are more interested in Russian fighter jets as opposed to Chinese. This has to do as much with regional geo-politics, political leverage and historical relations as it does with sheer necessity or practical application. The good old days of super friendly relations between the west and China (Obama era) are long gone. With China looking to surpass the west, western nations have recently shown quite a bit of animosity and hate towards China, pointing fingers at China in Hong Kong and XinJiang in particular. This has made China more receptive to doing business with Iran.
However Iranians are not going to forget the fact that for a while China & Russia were working hand in hand with the western nations hypocritical & unfair policies towards Iran, specifically in the nuclear field. In regards to the nuclear issue, the western nations treatment of Iran is no different than the uneven and unfair treaties imposed on China after the Opium wars. Despite everything Iran was willing to compromise with the world but as we have clearly seen the Americans and EU do not want to negotiate. Rather they want to impose strict terms on Iran, specifically unfair and uneven terms.
Such hypocrisy, deceit and condescending attitudes are completely unacceptable to the Iranian nation. The way things are going Iran will soon join the nuclear club unless the Americans/EU come to their senses and understand that the days of gunboat diplomacy, imperialism and colonialism are long gone. The world is changing, quickly turning into a multi-polar setting and some nations, specifically the US and UK, cannot handle losing their spots as domineering, hegemonic powers.
In the past, especially with UN weapons sanctions, it was impossible for Iran to purchase fighter jets from Russia or China. Today the situation is different but really Iran is only interested in technology transfers and because Russia and Iran have actively worked together in Syria, it seems extremely likely that Iran will be purchasing fighter jets from Russia rather than China.
Either way, neither Russia nor China will sell Iran game changing weapons and Iran has no illusions about its airforce being able to compete with western nations, for the time being anyways. Iran mostly relies on it's missiles, air defenses, proxies, unmanned platforms and other less conventional or asymmetrical methods for deterrence. To Iran fighter jets are just a necessary addition when it comes to its overall military doctrine, which is based on defense.
However Iran isn't just interested in fighter jets. Iran needs a long list of military hardware, including parts for tanks, helicopters, air defense technology etc. For the most part Iran is looking to build its own military hardware, but either under license or with limited foreign components. Iran is currently in a transitional phase. In 20-30 years, if all things go according to plan, Iran will be more or less fully self sufficient when it comes to producing world class military hardware.
JF-17 is no joke. Other than J-10, J-20, F-35, there isn't another plane other than JF-17 that has DSI.