When i discard the king and choose another player for trading hand. I dont know that when trading. Do I and that player reveal our hand for another choosing the card to trade. Or I will give him my card and choose randomly his 2 cardsEach player only has one card when it's not his turn.
I'm not sure what version you're using, as mine doesn't have a King, but if discarding the king trades your hand with another player, you put down your other card, the other player puts down their card, you pick up his card, they pick up yours.
You now have one card in your hand(their card), and they have one as well(yours). The next player draws a card and decides which to play/discard.
Hope this helps.