C#基础知识学习——浅表复制与深表复制（九）

C#中有两种类型变量，一种 是值类型变量，一种是引用类型变量。对于前者，复制是属于全盘复制；而对后者，一般的复制只是浅表复制，相当于只复制了在内存的地址。

浅表与深表复制区别

是否对实例对象中对应的对象类型进行内存复制

浅表与深表复制举例

由例子可见，实例2虽然对实例1进行了复制，但是实例2的ColorQian 的赋值 仍然对实例1造成了影响

  public class ColorQian  
        {
    
    
            public int red;
            public int green;
            public int blue;
            public ColorQian(int red, int green, int blue)
            {
    
    
                this.red = red;
                this.green = green;
                this.blue = blue;
            }
            
        }
         public class MyobjectQian : ICloneable
        {
    
     
            public int id;
            public string size;
            public ColorQian color;
            public MyobjectQian(int id, string size, ColorQian colorQian)
            {
    
    
                this.id = id;
                this.size = size;
                this.color = colorQian;
            }

            public object Clone()
            {
    
    
                return new MyobjectQian(this.id,this.size,this.color);
            }
           
            //重写Tostring方法
            public override string ToString()
            {
    
    
                var s = String.Format("id:{0},size:{1},color:({2},{3},{4})",
                    this.id, this.size, this.color.red, this.color.green, this.color.blue);
                return s;
            }
        }
         public void QianTest()
        {
    
    
            ColorQian colorQian = new ColorQian(25, 99, 80);
            MyobjectQian myobjectQian = new MyobjectQian(1001, "small", colorQian);


            MyobjectQian myobjectQian1 = (MyobjectQian)myobjectQian.Clone();
            myobjectQian1.size = "big";
            myobjectQian1.id = 8001;
           //ColorQian 浅表复制，只复制了地址
            myobjectQian1.color.red =111 ;
            myobjectQian1.color.blue = 111;
            myobjectQian1.color.green = 111;

            
            MyobjectQian myobject3 = (MyobjectQian)myobjectQian.Clone();
            myobject3.size = "narmal";
            myobject3.id = 9001;
            //深表复制：进行对象复制的时候，对象所有成员都重写分配空间
            myobject3.color = new ColorQian(100, 25, 89);
            Console.WriteLine(myobjectQian);
            Console.WriteLine(myobjectQian1);
            Console.WriteLine(myobject3);
        }

最直接的方法就是对每个类实现ICloneable接口的实现，从而实现深表复制，节约对象创建的时间

  public class Color:ICloneable
        {
    
    
            public int red;
            public int green;
            public int blue;
            public Color(int red, int green, int blue)
            {
    
    
                this.red = red;
                this.green = green;
                this.blue = blue;
            }
            //节约对象创建的时间
            public object Clone()
            {
    
    
                return new Color(red , green, blue);
            }
        }
          public class Myobject : ICloneable
        {
    
    
            public int id;
            public string size;
            public Color color;
            public Myobject(int id, string size, Color color)
            {
    
    
                this.id = id;
                this.size = size;
                this.color = color;
                 }
                  Color的浅表复制
                //  public object Clone()
                //  {
    
    
                //      return new Myobject(this.id, this.size, this.color);
                //  }
                //Color的深表复制
                public object Clone()
                {
    
    
                    return new Myobject(this.id, this.size, (Color)this.color.Clone());
                }
            //重写Tostring方法
            public override string ToString()
            {
    
    
                var s = String.Format("id:{0},size:{1},color:({2},{3},{4})",
                    this.id, this.size, this.color.red, this.color.green, this.color.blue);
                return s;
            }
        }
         public void test1()
        {
    
    
            Color color = new Color(25, 99, 80);
            Myobject myobject1 = new Myobject(1001, "small", color);

            //调用clone创建新的Myobject
            //在Clone时，出现对象引用的复制，为浅表复制，即只复制了该对象的地址，并没有重新分配地址
            Myobject myobject2 = (Myobject)myobject1.Clone();
            myobject2.size = "big";
            myobject2.id = 5001;

            //浅表复制
            myobject2.color.red = 165;
            myobject2.color.green = 56;
            myobject2.color.blue = 45;

           //深表复制：进行对象复制的时候，对象所有成员都重写分配空间
            Myobject myobject3 = (Myobject)myobject1.Clone();
            myobject3.size = "narmal";
            myobject3.id = 9001;
            myobject3.color = new Color(100, 25, 89);

            Console.WriteLine(myobject1);//Console打印对象的时候默认调用Tostring方法
            Console.WriteLine(myobject2);
            Console.WriteLine(myobject3);
        }