c#把一个List<>赋值给另一个list<>

Question

c#怎么把一个List<> A赋值给另一个list<> B，当B改变时不影响A里面的值

demo:

public class People {
        public string Name { get; set; }
        public int Age { get; set; }
    }
    class Program
    {
        static void Main(string[] args)
        {

            List<People> list1 = new List<People>
            {
                new People{
                  Age=12,
                  Name="张三"
                }
            };
            List<People> list2 = new List<People>();
            list1.ForEach(a => list2.Add(a));
            list2[0].Name = "王五";
            foreach (People model in list1) {
                Console.WriteLine(model.Name);
            }
            foreach (People model in list2)
            {
                Console.WriteLine(model.Name);
            }
            Console.ReadLine();
        }
    }

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Answer 1

我参考的是这个

http://bbs.csdn.net/topics/390149229

我用的是红线里面的代码，不知道可不可以

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Answer 2

Hello lctk,

根据你的代码，我进行测试了，输入的结果是一样的，也就是你改变B的结果，是会影响到A的结果。A和B都是指向同一块内存区域。

我建议你使用那个链接的第二种方法。

Best Regards,

Hart

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Answer 3

Hi,我的意思是我的demo就是第二种写法，不起作用

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Answer 4

Hi,

其实不是ForEach的原因，是A和B指向的people的对象是一样的，list的地址是不一样的，但是list里面的people还是指向同一块地址。

如果你用下面的代码

 foreach (var item in list1)
            {
                //list2.Add(new People() { Age = item.Age, Name = item.Name});
                list2.Add(item);
            }

如果你使用隐藏的方法就不会有问题，因为people对象也被改变也是不一样的。 Item其实拿的是一个引用，而不是值传递。

Best Regards,

Hart

---

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Answer 5

hi，请问这个用反射能不能简单点啊，怎么写？

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Answer 6

Hi,

你可以参考下面的代码：

list1.ForEach(a => list2.Add(new People() { Age = a.Age, Name = a.Name }));

没有简单的写法，你只要注意我们要修改 people的值就可以解决问题。

Best Regards,

Hart

---

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Answer 7

Hi,我的意思是赋值的时候必须一个一个属性赋值吗？有没有简便点的方法

new People() { Age = a.Age, Name = a.Name }

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Answer 8

目前我没有想到好的方法，我觉得赋值必须要一个个赋值。

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Answer 9

我觉得 list 不好用 用 sting[]  数组模式 很好用,想调哪个调哪个

Answer 10

看看这个
MemberwiseClone
http://www.cnblogs.com/gengaixue/archive/2012/07/11/2586411.html