C#中的对象深拷贝和浅拷贝

1. 浅拷贝

public class Person
{
    public Person()
    {
        this.Address = new Address();
    }
    public string Name { get; set; }
     public int Age { get; set; }
    public Address Address { get; set; }

    public Person Clone()
    {
        return (Person)this.MemberwiseClone();
    }
}

public class Address
{
    public string Street { get; set; }
    public string City { get; set; }
}

　　

2. 深拷贝

深拷贝是指不仅拷贝对象的值类型成员，而且还拷贝所有引用类型成员的实际对象。这意味着新的对象将拥有其引用类型成员的完全独立副本。

实现方式

• 反射
• 序列化
• 对象映射（三方开源如TinyMapper、AutoMapper）。

/// <summary>
/// 深拷贝
/// </summary>
public static void Copy2()
{
    Person person1 = new Person()
    {
        Name = "张三",
        Address = new Address()
        {
            City = "北京",
        }
    };

    //Person person2 = CreateDeepCopy(person1);//深拷贝1反射
    // Person person2 =JsonConvert.DeserializeObject<Person>(JsonConvert.SerializeObject(person1));//深拷贝2序列化
    Person person2 =person1.MapTo<Person,Person>();//深拷贝3对象映射
    //修改原对象的属性
    person1.Address.City = "上海";
    //修改副本对象的属性
    person2.Name = "李四";
    person2.Address.City = "昆明";
    string result = $"原对象{JsonConvert.SerializeObject(person1)}。副本{JsonConvert.SerializeObject(person2)}";
    MessageBox.Show($"深拷贝：原对象和副本不相互影响。{result}");
}


/// <summary>
/// 使用反射进行深拷贝
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="original"></param>
/// <returns></returns>
static T CreateDeepCopy<T>(T original)
{
    if (original == null)
    {
        return default(T);
    }

    Type type = original.GetType();
    object newObject = Activator.CreateInstance(type);

    foreach (FieldInfo fieldInfo in type.GetFields())
    {
        if (fieldInfo.IsStatic)
        {
            continue;
        }

        object value = fieldInfo.GetValue(original);
        fieldInfo.SetValue(newObject, CreateDeepCopy(value));
    }

    return (T)newObject;
}