C# List Copy

UserModel 略

List<UserModels> lstUser = new List<UserModels>{...}

Coyp:

　　var lstUserCopy = new List<UserModels>(lstUser.ToArray());

Test1:

　　lstUserCoyp.Add(new UserModels{...}); 

　　lstUser.length + 1 = lstUserCoyp.length       OK!

Test2:

　　lstUserCoyp[0].Birthday = DateTime.Parse("2014/12/31");

　　lstUser[0] 发成变化。   ERROR！

结论-----------------------------------------------------------------

var lstUserCopy = new List<UserModels>(lstUser) 如果是值类型可以使用。不适用于引用类型。

List.CopyTo() 方法也是如此，不是深度考备。

CopyTo考备的只是UserModel的值，而UserModel的值都只是UserModel对象的引用。

List深Copy------------------------------------------------------------------

model

[Serializable]

    public class UserModels:ICloneable

    {

        public string UserName { get; set; }

        public int Age { get; set; }

        public DateTime Birthday { get; set; }



        public object Clone()

        {

            MemoryStream stream = new MemoryStream();

            BinaryFormatter formatter = new BinaryFormatter();

            formatter.Serialize(stream, this);

            stream.Position = 0;

            var obj = formatter.Deserialize(stream) as UserModels;

            return obj;

        }

    }

View Code

list扩展方法

public static class Extensions

    {

        public static IList<T> Clone<T>(this IList<T> listToClone) where T:ICloneable

        {

            return listToClone.Select(item => (T)item.Clone()).ToList();

        }

    }

View Code

使用
var lstUserCopy = lstUser.Clone();