Question

假设我有一个自定义类CustomClass，我有一个派生自CollectionBase类的名为CustomClassCollection的集合。假设我做的是这样的事情：

CustomClassCollection a = new CustomClassCollection();
CustomClassCollection b = a;

当我更改a中的CustomClass元素时，b中的元素也会更改。我应该如何编写这些类，以便在我将a分配给b并更改b的元素时，a仍保持不变？

Answer 1

Clone需要IClonable（实施CustomClassCollection）或复制构造函数。

Answer 2

您也可以尝试使用MemberwiseClone();

YourType other = (YourType) YourInstance.MemberwiseClone();

链接：http://msdn.microsoft.com/fr-fr/library/system.object.memberwiseclone.aspx

Answer 3

您需要在内部集合中实施Clone方法。

在您可以对集合本身实现方法之后，克隆 source 集合的每个元素会将其添加到 destination 。

Answer 4

using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

[Serializable]
class CustomClass
{
    int _id;
    string _value;

    public CustomClass(int id, string value)
    {
        _id = id;
        _value = value;
    }
}

[Serializable]
class CustomClassCollection
{
    private IList<CustomClass> _list = null;

    public CustomClassCollection()
    {
        _list = new List<CustomClass>();
    }

    public void Add(CustomClass a)
    {
        _list.Add(a);
    }
}

public static class CloneManager
{
    public static T Clone<T>(this T source)
    {
        if (!typeof(T).IsSerializable)
        {
            throw new ArgumentException("The type must be serializable.", "source");
        }

        if (Object.ReferenceEquals(source, null))
        {
            return default(T);
        }

        IFormatter formatter = new BinaryFormatter();
        Stream stream = new MemoryStream();
        using (stream)
        {
            formatter.Serialize(stream, source);
            stream.Seek(0, SeekOrigin.Begin);
            return (T)formatter.Deserialize(stream);
        }
    }
}

使用它像：

        CustomClassCollection a = new CustomClassCollection();
        CustomClassCollection b = ObjectCopier.Clone<CustomClassCollection>(a);

        a.Add(new CustomClass(1, "A"));
        a.Add(new CustomClass(2, "B"));
        a.Add(new CustomClass(3, "C"));

        b.Add(new CustomClass(1, "A"));
        b.Add(new CustomClass(2, "B"));

按值传递自定义类

4 个答案: