单件(Singleton创建型模式)c#简单例子

需要生成一个实例时，可采用单件模式

例子中只可生成一个玩家，并对玩家进行测试。单线程例子如下：

namespace singletonpattern
{
    public partial class SingletonForm : Form
    {
        public SingletonForm()
        {
            InitializeComponent();
        }

        private void btnDisplay_Click(object sender, EventArgs e)
        {
            player player1 = player.GetPlayer;
            player1.jump = "跳一跳";
            player1.move = "走一走";//对player1赋值
            listBox1.Items.Add("------play1.jump,player1.move-------");
            listBox1.Items.AddRange(new string[] { player1.jump, player1.move });

            player player2 = player.GetPlayer;//未对player2赋值，但值与player1相同
            listBox1.Items.Add("------play2.jump,player2.move-------");
            listBox1.Items.AddRange(new string[] { player2.jump, player2.move });

            player1.jump = "跳一跳,跑一跑";
            player1.move = "走一走，看--看";//修改的player1，player2也被修改，说明是同一个类
            listBox1.Items.Add("------play2.jump,player2.move-------");
            listBox1.Items.AddRange(new string[] { player2.jump, player2.move });

            listBox1.Items.Add(object.ReferenceEquals(player1, player2));//显示为true,说明两个为同一个类

        }
    }
    class player
    {
        private player()//单例第一步，设构造函数为私有的。
        { }
        private static player getplayer;
        public static player GetPlayer//第二步获取单例
        {
            get
            {
                if (getplayer == null)//判断是否实例唯一
                {
                    getplayer = new player();
                }
                return getplayer;
            }

        }
         public string jump { get; set; }//单例中的属性
        public string move { get; set; }
    }
}

 private static player getplayer;
        public static player GetPlayer//第二步获取单例
        {
            get
            {
                if (getplayer == null)//判断是否实例唯一
                {
                    getplayer = new player();
                }
                return getplayer;
            }

        }

       public static readonly player GetPlayer = new player();//简化单例模式