Can you castle if you have been put in check?

Answer 1

You can castle if you have been put in check previously in the game and removed the check without moving your king (either by blocking or capturing the opponent's piece). You cannot castle if: (a)you are currently in check; (b)you move your king through an attacked square on the board during the castle; or (c)you have moved your king or castling rook at any point in the game.

Answer 2

You can only castle if all the squares involves are free. That means the king cannot be attacked, the square it's going to cannot be attacked, and the intermediate square cannot be attacked. If you're in check, then you are not permitted to castle out of it. If castling is the only move you could make, then this is checkmate, and you have lost.