public override Path Route(Road previous, int moveCount, Path result = null)
{
if (previous == null)
{
throw new ArgumentNullException(nameof(previous));
}
if (!CanEnterFrom(previous))
{
throw new ArgumentException($"无法通过{nameof(previous)}进入此道路", nameof(previous));
}
if (moveCount < 0)
{
throw new ArgumentOutOfRangeException(nameof(moveCount));
}
if (!Exits.Any( ))
{
throw new InvalidOperationException("没有可用的出口");
}
Path current = result ?? new Path( );
current.AddRoute(this);
if (BlockMoving || moveCount == 0)
{
return(current);
}
List <Road> exits = Exits.Where(road => road != previous).ToList( );
if (exits.Count == 0)
{
return(previous.Route(this, moveCount - 1, result));
}
return(exits.RandomItem( ).Route(this, moveCount - 1, result));
}
public override bool CanEnterFrom(Road road)
{
return(Entrances.Contains(road));
}
/// <summary> /// 获取能否从某个道路进入这个道路 /// </summary> /// <param name="road">前一个道路</param> /// <returns>能否进入</returns> public abstract bool CanEnterFrom(Road road);
/// <summary> /// 获取路径的末端和末端之前的路径 /// </summary> /// <param name="previous">前一个路径</param> /// <param name="moveCount">能延长的路径长度</param> /// <param name="result"></param> /// <returns>路径</returns> public abstract Path Route(Road previous, int moveCount, Path result = null);
