C# 克隆

一、浅克隆:
     在浅克隆中,如果原型对象的成员变量是值类型,将复制一份给克隆对象;如果原型对象的成员变量是引用类型,则将引用对象的地址复制一份给克隆对象,也就是说原型对象和克隆对象的成员变量指向相同的内存地址。简单来说,在浅克隆中,当对象被复制时只复制它本身和其中包含的值类型的成员变量,而引用类型的成员对象并没有复制,如图:
 

在C#中,通过实现ICloneable接口的Clone方法()调用MemberwiseClone方法)来实现浅克隆:


    public class WeeklyLog:ICloneable

    {

        public string Name { get; set; }

        public Student Student { get; set; }

 

        public object Clone()

        {

            return this.MemberwiseClone();

        }

    }

    {

        public string Address { get; set; }

    }

    static void Main(string[] args)

        {

            WeeklyLog log1 = new ProtoTypeTest.WeeklyLog();

            log1.Name = "log1";

            log1.Student = new ProtoTypeTest.Student() { Address = "haidian" };

 

            WeeklyLog log2 = (WeeklyLog)log1.Clone();//调用浅克隆方法

            Console.WriteLine(log1.Name);//log1

            Console.WriteLine(log2.Name);//log1

            Console.WriteLine(log1.Student.Address);//haidian

            Console.WriteLine(log2.Student.Address);//haidian

            Console.WriteLine(object.ReferenceEquals(log1, log2));//false

            log2.Name = "log2";//修改克隆的对象的name属性

            Console.WriteLine(log1.Name);//log1

            Console.WriteLine(log2.Name);//log2

            log2.Student.Address = "chaoyang";//修改克隆的对象的引用类型Student的Address属性

            Console.WriteLine(log1.Student.Address);//chaoyang

            Console.WriteLine(log2.Student.Address);//chaoyang

            Console.ReadLine();

 

        }

二、深克隆:

     在深克隆中,无论原型对象的成员变量是值类型还是引用类型,都将复制一份给克隆对象,深克隆将原型对象的所有引用对象也复制一份给克隆对象。简单来说,在深克隆中,除了对象本身被复制外,对象所包含的所有成员变量也将复制,如图:

在C#语言中,如果需要实现深克隆,可以通过序列化(Serialization)等方式来实现。序列化就是将对象写到流的过程,写到流中的对象是原有对象的一个拷贝,而原对象仍然存在于内存中。通过序列化实现的拷贝不仅可以复制对象本身,而且可以复制其引用的成员对象,因此通过序列化将对象写到一个流中,再从流里将其读出来,可以实现深克隆。需要注意的是能够实现序列化的对象其类必须实现Serializable接口,否则无法实现序列化操作。下面我们使用深克隆技术来实现工作周报和附件对象的复制,由于要将附件对象和工作周报对象都写入流中,因此两个类用Serializable标识可序列化:
 


 [Serializable]

    public class WeeklyLog

    {

        public string Name { get; set; }

        public Student Student { get; set; }

 

        public WeeklyLog DeepClone()

        {

            object obj = null;

            //将对象序列化成内存中的二进制流

            BinaryFormatter inputFormatter = new BinaryFormatter();

            MemoryStream inputStream;

            using (inputStream = new MemoryStream())

            {

                inputFormatter.Serialize(inputStream, this);

            }

            //将二进制流反序列化为对象

            using (MemoryStream outputStream = new MemoryStream(inputStream.ToArray()))

            {

                BinaryFormatter outputFormatter = new BinaryFormatter();

                obj = outputFormatter.Deserialize(outputStream);

            }

            return (WeeklyLog)obj;

        }

 

    }

 

    [Serializable]

    public class Student

    {

        public string Address { get; set; }

 

    }

<pre name="code" class="csharp">    static void Main(string[] args)

        {

            WeeklyLog log1 = new ProtoTypeTest.WeeklyLog();

            log1.Name = "log1";

            log1.Student = new ProtoTypeTest.Student() { Address = "haidian" };

 

            WeeklyLog log2 = (WeeklyLog)log1.DeepClone();//调用深克隆方法

            Console.WriteLine(log1.Name);//log1

            Console.WriteLine(log2.Name);//log1

            Console.WriteLine(log1.Student.Address);//haidian

            Console.WriteLine(log2.Student.Address);//haidian

            Console.WriteLine(object.ReferenceEquals(log1, log2));//false

            log2.Name = "log2";//修改克隆的对象的name属性

            Console.WriteLine(log1.Name);//log1

            Console.WriteLine(log2.Name);//log2

            log2.Student.Address = "chaoyang";//修改克隆的对象的引用类型Student的Address属性

            Console.WriteLine(log1.Student.Address);//haidian

            Console.WriteLine(log2.Student.Address);//chaoyang

            Console.ReadLine();

 

        }

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转载自blog.csdn.net/qq_23018459/article/details/87922212