About the deeply copy

In our program, we want to copy a object fully, and the object is nested, so when we design the class can using the copy constructor, there is a sample, you can run the code with CLR:

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace WebApplicationTest
{
  /// <summary>
  /// Summary description for TestDeepCopy.
  /// </summary>
  public class TestDeepCopy: System.Web.UI.Page
  {
    private void Page_Load(object sender, System.EventArgs e)
    {
      ClassLevel1 objClassLevel1 = new ClassLevel1();
      objClassLevel1.objClassLevel2 = new ClassLevel2();
      objClassLevel1.objClassLevel2.objClassLevel3 = new ClassLevel3();
      objClassLevel1.objClassLevel2.strClassLevel2 = "I am a string in level2 class";
      
      // using the instance of the ClassLevel1 to call
      // the copy constructor of ClassLevel1 class
      ClassLevel1 copyObjClassLevel1 = new ClassLevel1(objClassLevel1);
      Response.Write(copyObjClassLevel1.objClassLevel2.strClassLevel2);
    }

    #region Web Form Designer generated code
    override protected void OnInit(EventArgs e)
    {
      //
      // CODEGEN: This call is required by the ASP.NET Web Form Designer.
      //
      InitializeComponent();
      base.OnInit(e);
    }

    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void InitializeComponent()
    {
      this.Load += new System.EventHandler(this.Page_Load);
    }
    #endregion
  }

  public class ClassLevel3
  {
    // Member variable
    public string strClassLevel3;
    
    // Copy constructor
    public ClassLevel3(ClassLevel3 objClassLevel3)
    {
      this.strClassLevel3 = objClassLevel3.strClassLevel3;
    }
    
    // Default constructor
    public ClassLevel3(){}
  }

  public class ClassLevel2
  {
    // Member variable
    public string strClassLevel2;
    public ClassLevel3 objClassLevel3;
    
    // Copy constructor
    public ClassLevel2(ClassLevel2 ojbClassLevel2)
    {
      this.strClassLevel2 = ojbClassLevel2.strClassLevel2;
      this.objClassLevel3 = new ClassLevel3(ojbClassLevel2.objClassLevel3);
    }
    
    // Default constrcutor
    public ClassLevel2(){}
  }

  public class ClassLevel1
  {
    // Member variable
    public string strClassLevel1;
    public ClassLevel2 objClassLevel2;
    
    // Copy constructor 
    public ClassLevel1(ClassLevel1 ojbClassLevel1)
    {
      this.strClassLevel1 = ojbClassLevel1.strClassLevel1;

      //Call the Copy constructor of ClassLevel2
      this.objClassLevel2 = new ClassLevel2(ojbClassLevel1.objClassLevel2);
    }
    
    // Default constructor 
    public ClassLevel1(){}
  }
}