using System;

public class MyClass
{
   public void DisplayMessage()
   {
      Console.WriteLine( "Welcome to the Grade Book!" );
   }
} 

public class MyClassTest
{
   public static void Main( string[] args )
   {
      MyClass myMyClass = new MyClass();
      myMyClass.DisplayMessage();
   }
}

           
          

   


/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 18 - PropertiesVirtual Properties
// copyright 2000 Eric Gunnerson
using System;

public abstract class DrawingObject
{
    public abstract string Name
    {
        get;
    }
}
class Circle: DrawingObject
{
    string name = "Circle";
    
    public override string Name
    {
        get
        {
            return(name);
        }
    }
}

public class PropertiesVirtualProperties
{
    public static void Main()
    {
        DrawingObject d = new Circle();
        Console.WriteLine("Name: {0}", d.Name);
    }
}

           
          

   


/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 18 - PropertiesStatic Properties
// copyright 2000 Eric Gunnerson
class Color
{
    public Color(int red, int green, int blue)
    {
        this.red = red;
        this.green = green;
        this.blue = blue;
    }
    
    int    red;
    int    green;
    int    blue;
    
    public static Color Red
    {
        get
        {
            return(new Color(255, 0, 0));
        }
    }
    public static Color Green
    {
        get
        {
            return(new Color(0, 255, 0));
        }
    }
    public static Color Blue
    {
        get
        {
            return(new Color(0, 0, 255));
        }
    }
}

public class StaticProperties
{
    static void Main()
    {
        Color background = Color.Red;
    }
}

           
          

/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress L.P.
ISBN: 1-893115-62-3
*/

// 22 – DelegatesDelegates as Static Properties
// copyright 2000 Eric Gunnerson
using System;
class Container
{
public delegate int CompareItemsCallback(object obj1, object obj2);
public void SortItems(CompareItemsCallback compare)
{
// not a real sort, just shows what the
// inner loop code might do
int x = 0;
int y = 1;
object item1 = arr[x];
object item2 = arr[y];
int order = compare(item1, item2);
}
object[] arr; // items in the collection
}
class Employee
{
Employee(string name, int id)
{
this.name = name;
this.id = id;
}
public static Container.CompareItemsCallback SortByName
{
get
{
return(new Container.CompareItemsCallback(CompareName));
}
}
public static Container.CompareItemsCallback SortById
{
get
{
return(new Container.CompareItemsCallback(CompareId));
}
}
static int CompareName(object obj1, object obj2)
{
Employee emp1 = (Employee) obj1;
Employee emp2 = (Employee) obj2;
return(String.Compare(emp1.name, emp2.name));
}
static int CompareId(object obj1, object obj2)
{
Employee emp1 = (Employee) obj1;
Employee emp2 = (Employee) obj2;

if (emp1.id > emp2.id)
return(1);
if (emp1.id < emp2.id) return(-1); else return(0); } string name; int id; } public class DelegatesasStaticProperties { public static void Main() { Container employees = new Container(); // create and add some employees here employees.SortItems(Employee.SortByName); // employees is now sorted by name } } [/csharp]

   


/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 18 - PropertiesAccessors
// copyright 2000 Eric Gunnerson

public class PropertiesAccessors
{
    private string name;
    
    public string Name
    {
        get 
        {
            return name;
        }
        set 
        {
            name = value;
        }
    }
}

           
          

   


/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 18 - PropertiesSide Effects When Setting Values
// copyright 2000 Eric Gunnerson
using System;
using System.Collections;
class Basket
{
    internal void UpdateTotal()
    {
        total = 0;
        foreach (BasketItem item in items)
        {
            total += item.Total;
        }
    }
    
    ArrayList    items = new ArrayList();
    Decimal    total;
}
public class BasketItem
{
    BasketItem(Basket basket)
    {
        this.basket = basket;
    }
    public int Quantity
    {
        get
        {
            return(quantity);
        }
        set
        {
            quantity = value;
            basket.UpdateTotal();
        }
    }
    public Decimal Price
    {
        get
        {
            return(price);
        }
        set
        {
            price = value;
            basket.UpdateTotal();
        }
    }
    public Decimal Total
    {
        get
        {
            // volume discount; 10% if 10 or more are purchased
            if (quantity >= 10)
            return(quantity * price * 0.90m);
            else
            return(quantity * price); 
        }
    }
    
    int        quantity;     // count of the item
    Decimal    price;        // price of the item
    Basket     basket;       // reference back to the basket
}

           
          

   


/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 18 - PropertiesUse of Properties
// copyright 2000 Eric Gunnerson
using System;
public class Auto
{
    public Auto(int id, string name)
    {
        this.id = id;
        this.name = name;
    }
    
    // query to find # produced
    public int ProductionCount
    {
        get
        {
            if (productionCount == -1)
            {
                // fetch count from database here.
            }
            return(productionCount);
        }
    }
    public int SalesCount
    {
        get
        {
            if (salesCount == -1)
            {
                // query each dealership for data
            }
            return(salesCount);
        }
    }
    string name;
    int id;
    int productionCount = -1;
    int salesCount = -1;
}