Shadow inherited members

In this chapter you will learn:

  1. What is member shadow
  2. When to use new and virtual in member shaow

Member shadow

During the inheritance we may shadow the members from the parent class. For example,

class Shape{/*from  j  ava2  s  .c  om*/
  int Width;
}

class Rectangle: Shape{
  int Width;
}

The Width from the Rectangle shadows the Width from Shape.

To mark the hidden fields C# uses new modifier.

class Shape{/*  j a  va  2  s . c om*/
  int Width;
}

class Rectangle: Shape{
  new int Width;
}

new and virtual in member shadow

We can mark virtual member with new keyword. The different is shown in the following code.

using System;//from j a  va 2 s.c o m

public class BaseClass
{
    public virtual void MyMethod()
    {
        Console.WriteLine("BaseClass.MyMethod");
    }
}

public class Overrider : BaseClass
{
    public override void MyMethod() { Console.WriteLine("Overrider.MyMethod"); }
}

public class Hider : BaseClass
{
    public new void MyMethod() { Console.WriteLine("Hider.MyMethod"); }
}

class Program
{
    static void Main(string[] args)
    {
        Overrider over = new Overrider();
        BaseClass b1 = over;
        over.MyMethod();

        Hider h = new Hider();
        BaseClass b2 = h;
        h.MyMethod();

    }
}

The output:

Next chapter...

What you will learn in the next chapter:

  1. How to seal a member from overriding
  2. A demo showoing how to create sealed methods
Home » C# Tutorial » Class
Classes and Structs
Encapsulation
Class and Struct Accessibility
Members
Static Members
Class
Class instance variables
Class instance Methods
Class Inheritance
Class constructor
Default constructors
Parameters of constructors
Constructor overloading
Static Constructor
Destructor
Override destructor
new operator
Class field
Static Fields
Read only field
Field default value
const value
Abstract class
Static Class
Partial type
Methods
Method local variable
Method Overloading
Method overloading with ref and out
Type conversion and method overloading
Error in Method overloading
virtual methods
Override methods
Method Parameter
Pass parameters
ref parameters
out parameters
Variable parameter length
Optional parameters
Named parameters
static method
function Return
Recursive methods
Virtual methods and polymorphism
Cast
Shadow inherited members
Seal a member
this keyword
base keyword
base and name hiding
Access Specifiers
private
public
protected
internal
Indexer
String type indexer
Multidimensional indexer
Indexer overloading
Indexer to append
Indexer logic
Properties
Properties getter and setter
Accessibilities of properties
Automatic properties
Read only and write only property
Virtual properties
Abstract Properties
Static Properties
interface
interface implementation
Explicit interface implementation
Interface inheritance
Indexer in an interface
Interface Properties
struct and interface
virtual interface implementation
as operator
is operator
null reference
Nested classes
object class
ToString method
GetHashCode
Object initialization
Extension method
Struct Instances vs. Class Instances