c#学习笔记-深度复制 与浅度复制

 关于值类型和引用类型：

 

浅度复制(shallow copy)只复制值类型(char,int )的值，而对于引用类型不会复制，浅度复制可以通过派生于System.Object的MemberwiseClone()方法来完成，这是一个受保护的方法。因为他并没有考虑引用类型成员，因此新对象的引用成员就会指向源对象中的相同成员引用的对象

如果要创建成员的新实例(复制值，而不是复制引用)就需要用到深度复制(deep copy)

深度复制需要实现一个ICloneable接口，如果使用这个接口需要实现它包含的Clone()方法，这个方法返回一个System.Object的值，

下面看下浅度复制：

public class Company
    {
        public string value { get; set; }
    }

    public class Phone
    {
       public string color { get; set; }

       public  Company company = new Company();

        public Phone (string newCompany)
        {
            company.value = newCompany;
        }

        public object getCopy()
        {
            return MemberwiseClone();
        }
    }

 static void Main(string[] args)
        {
            Phone phone = new Phone("xiaomi");
            phone.color = "red";
            Phone phone1 = (Phone)phone.getCopy();            
            Console.WriteLine($"phone company:{phone.company.value} color: {phone.color}");
            Console.WriteLine($"phone1 company:{phone1.company.value} color: {phone1.color}");

            Console.WriteLine("浅度复制修改新对象的值");

            phone1.company.value = "huawei";
            phone1.color = "green";
            Console.WriteLine($"phone company:{phone.company.value} color: {phone.color}");
            Console.WriteLine($"phone1 company:{phone1.company.value} color: {phone1.color}");
            Console.ReadKey();

        }

实验现象：

浅度复制在后引用类型修改后，原对象也跟着发生了改变

修改这个问题，可以使用深度复制

public class Company
    {
        public string value { get; set; }
    }

    public class Phone:ICloneable
    {
       public string color { get; set; }

       public  Company company = new Company();

        public Phone (string newCompany)
        {
            company.value = newCompany;
        }

        public object getCopy()
        {
            return MemberwiseClone();
        }

        public object Clone()
        {
            Phone newPhone = new Phone(company.value);
            return newPhone;
            //newPhone.company.value = this.company.value;

        }
    }

 

static void Main(string[] args)
        {
            Phone phone = new Phone("xiaomi");
            phone.color = "red";
            Phone phone1 = (Phone)phone.Clone();            
            Console.WriteLine($"phone company:{phone.company.value} color: {phone.color}");
            Console.WriteLine($"phone1 company:{phone1.company.value} color: {phone1.color}");

            Console.WriteLine("浅度复制修改新对象的值");

            phone1.company.value = "huawei";
            phone1.color = "green";
            Console.WriteLine($"phone company:{phone.company.value} color: {phone.color}");
            Console.WriteLine($"phone1 company:{phone1.company.value} color: {phone1.color}");
            Console.ReadKey();

        }

 

实验现象