C# ICollection.LastOrDefault方法代码示例

 public static void CancelCardReservationsExceedingMaxConcurrentTickets(ICollection<ICardTuneReservationTicket> tickets, ICollection<CardDetail> freeCards, IDictionary<int, ITvCardHandler> cards)
 {
   if (freeCards != null && freeCards.Count > 2)
   {                        
     Log.Debug("CancelCardReservationsExceedingMaxConcurrentTickets: removing exceeding nr of tickets, only 2 allowed at a time but found {0}", tickets.Count);       
     while (freeCards.Count > 2)
     {
       CardDetail cardDetailForReservation = freeCards.LastOrDefault(); 
       if (cardDetailForReservation != null)
       {
         int idcard = cardDetailForReservation.Card.IdCard;
         CancelCardReservationAndRemoveTicket(cards[idcard], tickets);
         freeCards.Remove(cardDetailForReservation);
       }
     }
   }      
 }

        private PlayerAction ChooseCardWhenPlayingSecond(PlayerTurnContext context, ICollection<Card> orderedCardsByPower)
        {
            ICollection<Card> trumpCards = orderedCardsByPower
                                                .Where(x => x.Suit == context.TrumpCard.Suit)
                                                .ToArray();
                                                
            // If we have a bigger card of the same suit, we play it.
            var biggerCardOfSameSuit = orderedCardsByPower
                    .Where(x => x.Suit == context.FirstPlayedCard.Suit && x.GetValue() > context.FirstPlayedCard.GetValue())
                    .FirstOrDefault();

            // If we have a card of the same suit, we play it.
            if (biggerCardOfSameSuit != null)
            {
                return this.PlayCard(biggerCardOfSameSuit);
            }
            // If we don't have a card of the same suit, we play the smallest trump card
            else
            {
                // We will use trump cards only on strong opponent cards
                if (context.FirstPlayedCard.Type == CardType.Ten || context.FirstPlayedCard.Type == CardType.Ace)
                {
                    if (trumpCards.Count > 0)
                    {
                        return this.PlayCard(trumpCards.LastOrDefault());
                    }
                    else
                    {
                        return this.PlayCard(orderedCardsByPower.LastOrDefault());
                    }
                }

                return this.PlayCard(orderedCardsByPower.LastOrDefault());
            }
        }

 public static void CancelCardReservationsBasedOnMaxCardsLimit(ICollection<ICardTuneReservationTicket> tickets, ICollection<CardDetail> freeCards, int maxCards, IDictionary<int, ITvCardHandler> cards)
 {
   int exceedingCardsCount = freeCards.Count() - maxCards;
   if (exceedingCardsCount > 0)
   {
     if (tickets != null && tickets.Count > 0)
     {
       while (freeCards.Count() > exceedingCardsCount)
       {
         CardDetail cardDetailForReservation = freeCards.LastOrDefault();
         if (cardDetailForReservation != null)
         {
           int idcard = cardDetailForReservation.Card.IdCard;
           CancelCardReservationAndRemoveTicket(cards[idcard], tickets);
           freeCards.Remove(cardDetailForReservation);
         }
       }
     }
   }
 }

        private void ModifySelection(ICollection<object> itemsToSelect, ICollection<object> itemsToUnselect)
        {
            //clean up any duplicate or unnecessery input
            // check for itemsToUnselect also in itemsToSelect
            foreach (var item in itemsToSelect)
            {
                itemsToUnselect.Remove(item);
            }

            // check for itemsToSelect already in SelectedItems
            foreach (var item in SelectedItems)
            {
                itemsToSelect.Remove(item);
            }

            // check for itemsToUnSelect not in SelectedItems
            foreach (var item in itemsToUnselect.Where(x => !SelectedItems.Contains(x)).ToList())
            {
                itemsToUnselect.Remove(item);
            }

            //check if there's anything to do.
            if (itemsToSelect.Count == 0 && itemsToUnselect.Count == 0)
                return;

            allowedSelectionChanges = true;
            // Unselect and then select items
            foreach (var itemToUnSelect in itemsToUnselect)
            {
                SelectedItems.Remove(itemToUnSelect);
            }

            ((NonGenericObservableListWrapper<object>)SelectedItems).AddRange(itemsToSelect);
            allowedSelectionChanges = false;

            if (itemsToUnselect.Contains(lastShiftRoot))
                lastShiftRoot = null;

            if (!(SelectedItems.Contains(lastShiftRoot) && IsShiftKeyDown))
                lastShiftRoot = itemsToSelect.LastOrDefault();
        }