public Account(string owner, double initialAmount)
        {
            m_owner = owner;
            m_balance = initialAmount;

            m_state = new NormalState(this); //设置初始状态
        }
 public void SetState(AccountState state)
 {
     m_state = state;
 }
 public void SetState(AccountState state)
 {
     m_state = state;
 }