Csharp/C Sharp/Class Interface/Class Deriving

Demonstrates deriving a new class from a base class in another assembly

<source lang="csharp"> /* C# Programming Tips & Techniques by Charles Wright, Kris Jamsa Publisher: Osborne/McGraw-Hill (December 28, 2001) ISBN: 0072193794

• /

// // Access1.cs - demonstrates deriving a new class from a base class in // another assembly. Also demonstrates how a derived class // may provide a public property to expose a protected member // of a base class. // // Compile this program with the following command line: // C:>csc /r:access.exe Access1.cs // namespace nsAccess {

   using System;
   
   public class Access1
   {
       static public void Main ()
       {
           clsDerived derived = new clsDerived ();
           derived.AccessIt = 42;
           derived.ShowField ();
       }
   }

// // Derive a class from the base class and give it a public // property to access the private field in the base class

   class clsDerived : clsBase
   {
       public int AccessIt
       {
           get {return (Private);}
           set {Private = value;}
       }
   }
   public class clsBase
   {
       private int m_Private;
       protected int Private
       {
           get {return (m_Private);}
           set {m_Private = value;}
       }
       public void ShowField ()
       {
           Console.WriteLine ("The value of private field m_Private is " + m_Private);
       }
   }
   

}

      </source>

the overridden methods of the System.Object class

<source lang="csharp"> using System; using System.Collections;

public class Starter {

   public static void Main() {
       Employee obj1 = new Employee(5678);
       Employee obj2 = new Employee(5678);
       if (obj1 == obj2) {
           Console.WriteLine("equals");
       } else {
           Console.WriteLine("not equals");
       }
   }

} class Employee {

   public Employee(int id) {
       if ((id < 1000) || (id > 9999)) {
           throw new Exception(
               "Invalid Employee ID");
       }
       propID = id;
   }
   public static bool operator ==(Employee obj1, Employee obj2) {
       return obj1.Equals(obj2);
   }
   public static bool operator !=(Employee obj1, Employee obj2) {
       return !obj1.Equals(obj2);
   }
   public override bool Equals(object obj) {
       Employee _obj = obj as Employee;
       if (obj == null) {
           return false;
       }
       return this.GetHashCode() == _obj.GetHashCode();
   }
   public override int GetHashCode() {
       return EmplID;
   }
   public string FullName {
       get {
           return propFirst + " " +
               propLast;
       }
   }
   private string propFirst;
   public string First {
       get {
           return propFirst;
       }
       set {
           propFirst = value;
       }
   }
   private string propLast;
   public string Last {
       get {
           return propLast;
       }
       set {
           propLast = value;
       }
   }
   private readonly int propID;
   public int EmplID {
       get {
           return propID;
       }
   }
   public override string ToString() {
       return FullName;
   }

}

</source>