Buecherwurm/Lend_Administration.cs

using System.Collections.Generic;

namespace Bücherwurm
{
    class Lend_Administration
    {
        private List<Lending> Lendings {get; set;}

        private List<int> ActiveLendings {get; set;}

        private int NextId {get; set;}

        public Lend_Administration()
        {
            Lendings = new List<Lending>();
            ActiveLendings = new List<int>();
            NextId = 0;
        }

        public void Lend(int[] ItemIds, string Customer)
        {
            Lendings.Add(new Lending(NextId, ItemIds, Customer));
            ActiveLendings.Add(NextId);
            NextId = NextId++;
        }

        public void Return(int LendID)
        {
            ActiveLendings.RemoveAll(id => id == LendID);
        }
    }
}