C # shallow replication and deep Replication

Recently, I encountered a complicated copying problem of classes.

In. net, all classes have a memberwiseclone method that inherits the object. The memberwiseclone method provides shallow replication of classes. Why is it a light copy? When the memberwiseclone method is used for copying, a new variable is created for the value type in the class, and the referenced variable points to the original reference and does not create a new reference variable, for more information, see the following link.

Http://msdn.microsoft.com/zh-cn/library/system.object.memberwiseclone.aspx

Msdn provides a simple method to implement deep replication of classes that contain reference types. However, if a class contains the list attribute, list itself is a reference type, the "=" symbol does not generate a copy of the list, but only copies the reference. Therefore, an iteration is required to copy the entire list. Use the code to summarize deep replication:

Class Program
{
Static void main (string [] ARGs)
{
School school1 = New School ();
// Call the clone method of school to create a deep copy
School school2 = (school) school1.clone ();

// Modify the attributes of school1 to see if it will affect school2.
School1.president. Name = "Liu ";
School1.grades [0]. ID = 3;
School1.buildings [0] = "Third Floor ";

Console. Readline ();
}
}

Public class school: icloneable
{
Public String city {Get; set ;}
Public string name {Get; set ;}
Public President {Get; set ;}
Public list <Grade> grades {Get; set ;}
Public list <string> buildings {Get; set ;}

/// <Summary>
/// Initialize School
/// </Summary>
Public School ()
{
City = "City ";
Name = "City a No. 1 ";

President = new president
{
Age = 50,
Name = "Zhang"
};

Grades = new list <Grade> ();
Grades. Add (new grade {id = 1, name = "First Grade "});
Grades. Add (new grade {id = 2, name = ""});

Buildings = new list <string> ();
Buildings. Add ("1st Floor ");
Buildings. Add ("Floor 2 ");
}

/// <Summary>
/// Deep copy School
/// </Summary>
/// <Returns> deep copy </returns>
Public object clone ()
{
// Copy a copy.
School newschool = (school) This. memberwiseclone ();

// Call the clone method of President to create a new object for President
Newschool. President = (President) This. President. Clone ();

// Clear two lists
Newschool. Grades = new list <Grade> ();
Newschool. Buildings = new list <string> ();

// Add grades to the new school
Foreach (VAR grade in grades)
{
Newschool. Grades. Add (grade) grade. Clone (); // copy by calling the clone method of Grade
}

// Add buildings to the new school
Foreach (VAR building in buildings)
{
Newschool. Buildings. Add (building );
// Although the string type is a reference type. in the. NET Framework, the "=" symbol is used to create a new String object in the heap, so you can copy the string without using the clone method.
// Newschool. Buildings. Add (string) Building. Clone ());
}

Return newschool;
}
}

Public class grade: icloneable
{
Public int ID {Get; set ;}
Public string name {Get; set ;}

Public object clone ()
{
Return this. memberwiseclone ();
}
}

Public class president: icloneable
{
Public int age {Get; set ;}
Public string name {Get; set ;}

Public object clone ()
{
Return this. memberwiseclone ();
}
}

Public class person: icomparable
{
Public String firstname;
Public String lastname;

Public Person ()
{}

Public Person (string first, string last)
{
Firstname = first;
Lastname = last;
}

Public int compareto (Object OBJ)
{
Person Other = OBJ as person;
Int result = This. lastname. compareto (other. lastname );
This. memberwiseclone ();
Return result;
}
}

 

The above is the general usage method of deep replication. Using this method, we can find that there are more simple methods on the Internet, so we don't need to implement the clone method of the icloneable interface. serialization solves this problem. You can refer to this document in workshop.

Http://www.cnblogs.com/zhangji/archive/2011/02/23/1961897.html