c#中的对象大体分为值类型和引用类型,值类型大致包括 int, struct等,引用类型大致包括 自定义Class,object 等。string属于特殊的引用类型,不在本文的讨论之内。
值类型直接存储对象,而引用类型存储对象的地址,在对引用类型进行复制的时候,也只是复制对象的地址。
完全复制一个引用类型对象主要有几种方法:
1.添加一个Copy函数,进行拷贝(如果字段为引用类型,需要循环添加Copy函数,这样情况会变的十分复杂。)
namespace ConsoleApplication1
{
class User
{
public string Name { get; set; }
public string Sex { get; set; }
public House Home { get; set; }
public User Copy()
{
User newUser = (User)this.MemberwiseClone();
newUser.Home = this.Home.Copy();
return newUser;
}
}
class House
{
public string Address { get; set; }
public House Copy()
{
return (House)this.MemberwiseClone();
}
}
class Program
{
static void Main(string[] args)
{
User a = new User();
a.Name = "A";
a.Home = new House() { Address = "长江路" };
User b = a.Copy();
b.Name = "B";
b.Home.Address = "黄河路";
Console.WriteLine(a.Name);
Console.WriteLine(a.Home.Address);
Console.ReadLine();
}
}
}
2.利用序列化反序列化(对性能会有杀伤)
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using System.Threading.Tasks;namespace Test
{
class Program
{
static void Main(string[] args)
{
Test t1 = new Test();
Console.WriteLine(t1.list.Count);
Test t2 = (Test)Clone(t1);
t2.list.Add("");
Console.WriteLine(t2.list.Count);
Console.WriteLine(t1.list.Count);
Console.ReadLine();
} public static object Clone(object obj)
{
BinaryFormatter bf = new BinaryFormatter();
MemoryStream ms = new MemoryStream();
bf.Serialize(ms, obj);
ms.Position = ;
return (bf.Deserialize(ms)); ;
}
} [Serializable]
public class Test
{
public List<string> list = new List<string>();
}
}
3.利用反射(测试了一个网上的接口可用,但是对性能杀伤和序列化反序列化相当,而且可能对代码混淆有一定影响。 https://www.cnblogs.com/zhili/p/DeepCopy.html)
最后附上微软文档:
https://docs.microsoft.com/zh-cn/dotnet/api/system.object.memberwiseclone?redirectedfrom=MSDN&view=netframework-4.7.2#System_Object_MemberwiseClone