Mega Code Archive
0138 virtual members
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A virtual member can be overriden by its subclasses.
A virtual member is marked by the virtual keyword.
A virtual feature can be a method, a property, an indexer or an event.
The following code shows how to use the virtual method to provide the different implementation of the Area.
using System;
class Shape{
public virtual double Area{
get{
return 0;
}
}
}
class Rectangle:Shape{
public int width;
public int height;
public override double Area{
get{
return width * height;
}
}
}
class Circle:Shape{
public int radius;
public override double Area{
get{
return 3.14 * radius * radius;
}
}
}
class Program
{
static void Main(string[] args)
{
Rectangle r = new Rectangle();
r.width = 4;
r.height = 5;
Circle c = new Circle();
c.radius = 6;
Console.WriteLine(r.Area);
Console.WriteLine(c.Area);
}
}
The output:
20
113.04
C# requires that the virtual and override must have the same signature, accessor and return type.
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