It evolves if you are training it with an Up-Grade
You can give the Upgrade to Porygon and then trade it to a friend to make Porygon evolve into Porygon2, in order to evolve Porygon2 then give a Dubious Disc to Porygon2 and then trade it to someone and it'll evolve into a Porygon-Z.
Porygon-Z is the final form of Porygon (and Porygon2). To evolve Porygon to Porygon2, trade it while it holds an Up-Grade item. To evolve Porygon2 to Porygon-Z, trade it while it holds a Dubious Disc item.
To evolve it into a Porygon2, trade Porygon holding an Up-Grade. To evolve Porygon 2 into Porygon-Z, trade Porygon2 holding a dubious disc
If you trade a porygon with an upgrade it will evolve into porygon2 =0
Evolving porygon into porygon2. Have porygon hold the upgrade then trade it. It will evolve into porygon2
Make porygon2 hold a dubious disk Then trade it in order to evolve
Just Evolve Porygon(1). And To Evolve Porygon(1),You Must Trade It.
Catch pokemon, battle, almost all the same stuff as the other games.
To evolve Porygon in Pokemon Platinum you need to trade it while it is holding the Up-Grade item. This will evolve Porygon into Porygon2. If Porygon2 is traded while holding a Dubious Disc it will evolve into Porygon-Z.
You cannot catch Porygon2 in the wild, you will have to trade a Porygon holding an Up-grade to evolve it into Porygon2.
you have to have a upgrade and then trade it
train it