I understand how they work (basically), but I think maybe the examples
I'm reading are too elementary to really show their value. Here's one
from Programming C#:
#region Using directives
using System;
using System.Collections.Generic;
using System.Text;
#endregion
namespace SimpleInterface
{
// declare the interface
interface IStorable
{
// no access modifiers, methods are public
// no implementation
void Read();
void Write( object obj );
int Status { get; set; }
}
// create a class which implements the IStorable interface
public class Document : IStorable
{
// store the value for the property
private int status = 0;
public Document( string s )
{
Console.WriteLine( "Creating document with: {0}", s );
}
// implement the Read method
public void Read()
{
Console.WriteLine(
"Implementing the Read Method for IStorable" );
}
// implement the Write method
public void Write( object o )
{
Console.WriteLine(
"Implementing the Write Method for IStorable" );
}
// implement the property
public int Status
{
get
{
return status;
}
set
{
status = value;
}
}
}
// Take our interface out for a spin
public class Tester
{
static void Main()
{
// access the methods in the Document object
Document doc = new Document( "Test Document" );
doc.Status = -1;
doc.Read();
Console.WriteLine( "Document Status: {0}", doc.Status );
}
}
}
My question is, what is gained by even using the interface? If you have
to implement the methods and property in the class anyway, couldn't you
just leave the class as it is, without the interface, and it would still
work?
