/// <summary>
/// 初始化状态机时，构造一个状态机
/// </summary>
void ConstructFSM()
{
FSM = new FSMSystem();
AttackState attackState = new AttackState(gameObject);
attackState.AddTransition(Transition.LostEnemy, StateID.Wander);
MoveToState moveToState = new MoveToState(gameObject, MoveTarget);
moveToState.AddTransition(Transition.ReadyToAttack, StateID.Attack);
moveToState.AddTransition(Transition.LostEnemy, StateID.Wander);
WanderState wanderState = new WanderState(gameObject, wanderPoints);
wanderState.AddTransition(Transition.SawEnemy, StateID.MoveTo);
wanderState.AddTransition(Transition.SawItem, StateID.MoveTo);
FSM.AddState(attackState);
FSM.AddState(wanderState);
FSM.AddState(moveToState);
FSM.start(StateID.Wander);
}