public sealed class ContactPerson
{
    //姓名
    public string Name { get; set; }
    //電話號(hào)碼
    public string MobileNumber { get; set; }
}

public sealed class MobileBackOriginator
{
    // 發(fā)起人需要保存的內(nèi)部狀態(tài)
    private List<ContactPerson> _personList;

    public List<ContactPerson> ContactPersonList
    {
        get
        {
            return this._personList;
        }
        set
        {
            this._personList = value;
        }
    }
    //初始化需要備份的電話名單
    public MobileBackOriginator(List<ContactPerson> personList)
    {
        if (personList != null)
        {
            this._personList = personList;
        }
        else
        {
            throw new ArgumentNullException("參數(shù)不能為空！");
        }
    }
    // 創(chuàng)建備忘錄對(duì)象實(shí)例，將當(dāng)期要保存的聯(lián)系人列表保存到備忘錄對(duì)象中
    public ContactPersonMemento CreateMemento()
    {
        return new ContactPersonMemento(new List<ContactPerson>(this._personList));
    }
    // 將備忘錄中的數(shù)據(jù)備份還原到聯(lián)系人列表中
    public void RestoreMemento(ContactPersonMemento memento)
    {
        this.ContactPersonList = memento.ContactPersonListBack;
    }
    public void Show()
    {
        Console.WriteLine("聯(lián)系人列表中共有{0}個(gè)人，他們是:", ContactPersonList.Count);
        foreach (ContactPerson p in ContactPersonList)
        {
            Console.WriteLine("姓名: {0} 號(hào)碼: {1}", p.Name, p.MobileNumber);
        }
    }
}

public sealed class ContactPersonMemento
{
    // 保存發(fā)起人創(chuàng)建的電話名單數(shù)據(jù)，就是所謂的狀態(tài)
    public List<ContactPerson> ContactPersonListBack { get; private set; }
    public ContactPersonMemento(List<ContactPerson> personList)
    {
        ContactPersonListBack = personList;
    }
}

public sealed class MementoManager
{
    //如果想保存多個(gè)【備忘錄】對(duì)象，可以通過(guò)字典或者堆棧來(lái)保存，堆棧對(duì)象可以反映保存對(duì)象的先后順序
    //比如：public Dictionary<string, ContactPersonMemento> ContactPersonMementoDictionary { get; set; }
    public ContactPersonMemento ContactPersonMemento { get; set; }
}

class Program
{
    static void Main(string[] args)
    {
        List<ContactPerson> persons = new List<ContactPerson>()
            {
                new ContactPerson() { Name="黃飛鴻", MobileNumber = "13533332222"},
                new ContactPerson() { Name="方世玉", MobileNumber = "13966554433"},
                new ContactPerson() { Name="洪熙官", MobileNumber = "13198765544"}
            };
        //手機(jī)名單發(fā)起人
        MobileBackOriginator mobileOriginator = new MobileBackOriginator(persons);
        mobileOriginator.Show();
        // 創(chuàng)建備忘錄并保存?zhèn)渫泴?duì)象
        MementoManager manager = new MementoManager();
        manager.ContactPersonMemento = mobileOriginator.CreateMemento();
        // 更改發(fā)起人聯(lián)系人列表
        Console.WriteLine("----移除最后一個(gè)聯(lián)系人--------");
        mobileOriginator.ContactPersonList.RemoveAt(2);
        mobileOriginator.Show();
        // 恢復(fù)到原始狀態(tài)
        Console.WriteLine("-------恢復(fù)聯(lián)系人列表------");
        mobileOriginator.RestoreMemento(manager.ContactPersonMemento);
        mobileOriginator.Show();
        Console.Read();
    }
}