ConcurrentDictionary的ToDictionary

如果Value是引用，那么在使用Value.Clear()的时候。会清空Value的所有元素，但是不会改变Value的引用

 private static void Main()
        {
            try
            {
                var concurrentDictionary = new ConcurrentDictionary<string, List<int>>();
                concurrentDictionary.TryAdd("chuck", new List<int>() {1, 2, 3});
                concurrentDictionary.TryAdd("lihu", new List<int>() {4, 5, 6});

                var dictionary = concurrentDictionary.ToDictionary(x => x.Key, x => x.Value);
                foreach (var list in concurrentDictionary.Values)
                {
                    list.Clear();
                }

                foreach (var name in dictionary.Keys)
                {
                    Console.WriteLine(name);
                    var list = dictionary[name];
                    foreach (var number in list)
                    {
                        Console.Write("\t{0}",number);
                    }
                    Console.WriteLine();
                }

            }
            catch (Exception ex)
            {
                while (ex != null)
                {
                    Console.WriteLine(ex.Message);
                    ex = ex.InnerException;
                }
            }
            Console.ReadLine();
        }

还需要测试下Value是List<Student>的情况 

 

 

internal class Student
    {
        internal int Id { get; set; }
        internal string Name { get; set; }
    }

    internal class Program
    {
        private static void Main()
        {
            try
            {
                var concurrentDictionary = new ConcurrentDictionary<string, Student>();
                concurrentDictionary.TryAdd("chuck", new Student() {Id = 1, Name = "chuck"});
                concurrentDictionary.TryAdd("lihu", new Student() {Id = 2, Name = "lihu"});

                var dictionary = concurrentDictionary.ToDictionary(x => x.Key, x => x.Value);
                foreach (var key in concurrentDictionary.Keys)
                {
                    concurrentDictionary[key].Id = 0;
                    concurrentDictionary[key].Name = "hello world";
                }

                foreach (var name in dictionary.Keys)
                {
                    Console.Write(name);
                    Console.Write("\tid={0}\tname={1}", dictionary[name].Id, dictionary[name].Name);
                    Console.WriteLine();
                }

            }
            catch (Exception ex)
            {
                while (ex != null)
                {
                    Console.WriteLine(ex.Message);
                    ex = ex.InnerException;
                }
            }
            Console.ReadLine();
        }
    }

 

 

 

 

 

 Value是值类型的

 private static void Main()
        {
            try
            {
                var concurrentDictionary = new ConcurrentDictionary<string, int>();
                concurrentDictionary.TryAdd("chuck", 1);
                concurrentDictionary.TryAdd("lihu",4);

                var dictionary = concurrentDictionary.ToDictionary(x => x.Key, x => x.Value);
                foreach (var key in concurrentDictionary.Keys)
                {
                    concurrentDictionary[key] = 0;
                }

                foreach (var name in dictionary.Keys)
                {
                    Console.Write(name);
                    Console.Write("\t{0}", dictionary[name]);
                    Console.WriteLine();
                }

            }
            catch (Exception ex)
            {
                while (ex != null)
                {
                    Console.WriteLine(ex.Message);
                    ex = ex.InnerException;
                }
            }
            Console.ReadLine();
        }

 

作者:Chuck Lu    GitHub