C#多线程怎么锁定全局变量

主线程和子线程全局变量共享数据public static Dictionary<string, DateTime> dictionary = new Dictionary<string, DateTime>();    public static object locker = new object();//添加一个对象作为锁    public static void AddRecord()//线程1循环调用此函数    {        lock (locker)//锁        {            /*添加过程*/            dictionary.Add("....", DateTime.Now);        }    }    public static void DeleteRecord()//线程2循环调用此函数    {        lock (locker)//锁        {            /*删除过程*/            dictionary.Remove("....");        }    }