illustrates implementing multiple interfaces

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/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/
/*
  Example8_2.cs illustrates implementing multiple interfaces
*/

using System;


// define the IDrivable interface
public interface IDrivable
{

  // method declarations
  void Start();
  void Stop();

  // property declaration
  bool Started
  {
    get;
  }

}


// define the ISteerable interface
public interface ISteerable
{

  // method declarations
  void TurnLeft();
  void TurnRight();

}


// Car class implements the IMovable interface
class Car : IDrivable, ISteerable
{

  // declare the underlying field used by the
  // Started property of the IDrivable interface
  private bool started = false;

  // implement the Start() method of the IDrivable interface
  public void Start()
  {
    Console.WriteLine("car started");
    started = true;
  }

  // implement the Stop() methodof the IDrivable interface
  public void Stop()
  {
    Console.WriteLine("car stopped");
    started = false;
  }

  // implement the Started property of the IDrivable interface
  public bool Started
  {
    get
    {
      return started;
    }
  }

  // implement the TurnLeft() method of the ISteerable interface
  public void TurnLeft()
  {
    Console.WriteLine("car turning left");
  }
  
  // implement the TurnRight() method of the ISteerable interface
  public void TurnRight()
  {
    Console.WriteLine("car turning right");
  }

}


public class Example8_2
{

  public static void Main()
  {

    // create a Car object
    Car myCar = new Car();

    // call myCar.Start()
    Console.WriteLine("Calling myCar.Start()");
    myCar.Start();

    // call myCar.TurnLeft()
    Console.WriteLine("Calling myCar.TurnLeft()");
    myCar.TurnLeft();

  }

}


           
          


illustrates interfaces

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/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/
/*
  Example8_1.cs illustrates interfaces
*/

using System;


// define the IDrivable interface
public interface IDrivable
{

  // method declarations
  void Start();
  void Stop();

  // property declaration
  bool Started
  {
    get;
  }

}


// Car class implements the IDrivable interface
class Car : IDrivable
{

  // declare the underlying field used by the Started property
  private bool started = false;

  // implement the Start() method
  public void Start()
  {
    Console.WriteLine("car started");
    started = true;
  }

  // implement the Stop() method
  public void Stop()
  {
    Console.WriteLine("car stopped");
    started = false;
  }

  // implement the Started property
  public bool Started
  {
    get
    {
      return started;
    }
  }
  
}


public class Example8_1
{

  public static void Main()
  {

    // create a Car object
    Car myCar = new Car();

    // call myCar.Start()
    myCar.Start();
    Console.WriteLine("myCar.Started = " + myCar.Started);

    // call myCar.Stop()
    myCar.Stop();
    Console.WriteLine("myCar.Started = " + myCar.Started);

  }

}


           
          


Using interface 3

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/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
using System;

// An encryption interface.
public interface ICipher {
string encode(string str);
string decode(string str);
}

/* A simple implementation of ICipher that codes
a message by shifting each character 1 position
higher. Thus, A becomes B, and so on. */
class SimpleCipher : ICipher {

// Return an encoded string given plaintext.
public string encode(string str) {
string ciphertext = “”;

for(int i=0; i < str.Length; i++) ciphertext = ciphertext + (char) (str[i] + 1); return ciphertext; } // Return an decoded string given ciphertext. public string decode(string str) { string plaintext = ""; for(int i=0; i < str.Length; i++) plaintext = plaintext + (char) (str[i] - 1); return plaintext; } } /* This implementation of ICipher uses bit manipulations and key. */ class BitCipher : ICipher { ushort key; // Specify a key when constructing BitCiphers. public BitCipher(ushort k) { key = k; } // Return an encoded string given plaintext. public string encode(string str) { string ciphertext = ""; for(int i=0; i < str.Length; i++) ciphertext = ciphertext + (char) (str[i] ^ key); return ciphertext; } // Return an decoded string given ciphertext. public string decode(string str) { string plaintext = ""; for(int i=0; i < str.Length; i++) plaintext = plaintext + (char) (str[i] ^ key); return plaintext; } } // Use ICipher. // A class for storing unlisted telephone numbers. class UnlistedPhone { string pri_name; // supports name property string pri_number; // supports number property ICipher crypt; // reference to encryption object public UnlistedPhone(string name, string number, ICipher c) { crypt = c; // store encryption object pri_name = crypt.encode(name); pri_number = crypt.encode(number); } public string Name { get { return crypt.decode(pri_name); } set { pri_name = crypt.encode(value); } } public string Number { get { return crypt.decode(pri_number); } set { pri_number = crypt.encode(value); } } } // Demonstrate UnlistedPhone public class UnlistedDemo { public static void Main() { UnlistedPhone phone1 = new UnlistedPhone("Tom", "555-3456", new BitCipher(27)); UnlistedPhone phone2 = new UnlistedPhone("Mary", "555-8891", new BitCipher(9)); Console.WriteLine("Unlisted number for " + phone1.Name + " is " + phone1.Number); Console.WriteLine("Unlisted number for " + phone2.Name + " is " + phone2.Number); } } [/csharp]

Two class inherit one interface

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/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
using System;

// An encryption interface.
public interface ICipher {
string encode(string str);
string decode(string str);
}

/* A simple implementation of ICipher that codes
a message by shifting each character 1 position
higher. Thus, A becomes B, and so on. */
class SimpleCipher : ICipher {

// Return an encoded string given plaintext.
public string encode(string str) {
string ciphertext = “”;

for(int i=0; i < str.Length; i++) ciphertext = ciphertext + (char) (str[i] + 1); return ciphertext; } // Return an decoded string given ciphertext. public string decode(string str) { string plaintext = ""; for(int i=0; i < str.Length; i++) plaintext = plaintext + (char) (str[i] - 1); return plaintext; } } /* This implementation of ICipher uses bit manipulations and key. */ class BitCipher : ICipher { ushort key; // Specify a key when constructing BitCiphers. public BitCipher(ushort k) { key = k; } // Return an encoded string given plaintext. public string encode(string str) { string ciphertext = ""; for(int i=0; i < str.Length; i++) ciphertext = ciphertext + (char) (str[i] ^ key); return ciphertext; } // Return an decoded string given ciphertext. public string decode(string str) { string plaintext = ""; for(int i=0; i < str.Length; i++) plaintext = plaintext + (char) (str[i] ^ key); return plaintext; } } // Demonstrate ICipher. public class ICipherDemo { public static void Main() { ICipher ciphRef; BitCipher bit = new BitCipher(27); SimpleCipher sc = new SimpleCipher(); string plain; string coded; // first, ciphRef refers to the simple cipher ciphRef = sc; Console.WriteLine("Using simple cipher."); plain = "testing"; coded = ciphRef.encode(plain); Console.WriteLine("Cipher text: " + coded); plain = ciphRef.decode(coded); Console.WriteLine("Plain text: " + plain); // now, let ciphRef refer to the bitwise cipher ciphRef = bit; Console.WriteLine(" Using bitwise cipher."); plain = "testing"; coded = ciphRef.encode(plain); Console.WriteLine("Cipher text: " + coded); plain = ciphRef.decode(coded); Console.WriteLine("Plain text: " + plain); } } [/csharp]

Use explicit implementation to remove ambiguity

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/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/


// Use explicit implementation to remove ambiguity. 
 
using System; 
 
interface IMyIF_A { 
  int meth(int x); 
} 
 
interface IMyIF_B { 
  int meth(int x); 
} 
 
// MyClass implements both interfaces. 
class MyClass : IMyIF_A, IMyIF_B { 
 
  // explicitly implement the two meth()s 
  int IMyIF_A.meth(int x) { 
    return x + x; 
  } 
  int IMyIF_B.meth(int x) { 
    return x * x; 
  } 
 
  // call meth() through an interface reference. 
  public int methA(int x){ 
    IMyIF_A a_ob; 
    a_ob = this; 
    return a_ob.meth(x); // calls IMyIF_A 
  } 
 
  public int methB(int x){ 
    IMyIF_B b_ob; 
    b_ob = this; 
    return b_ob.meth(x); // calls IMyIF_B 
  } 
} 
 
public class FQIFNames { 
  public static void Main() { 
    MyClass ob = new MyClass(); 
 
    Console.Write("Calling IMyIF_A.meth(): "); 
    Console.WriteLine(ob.methA(3)); 
 
    Console.Write("Calling IMyIF_B.meth(): "); 
    Console.WriteLine(ob.methB(3)); 
  } 
}

           
          


Explicitly implement an interface member

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/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/


// Explicitly implement an interface member. 
 
using System; 
 
interface IEven { 
  bool isOdd(int x); 
  bool isEven(int x); 
} 
 
class MyClass : IEven { 
  // explicit implementation 
  bool IEven.isOdd(int x) { 
    if((x%2) != 0) return true; 
    else return false; 
  } 
 
  // normal implementation 
  public bool isEven(int x) { 
    IEven o = this; // reference to invoking object 
 
    return !o.isOdd(x); 
  } 
} 
 
public class Demo { 
  public static void Main() { 
    MyClass ob = new MyClass(); 
    bool result; 
 
    result = ob.isEven(4); 
    if(result) Console.WriteLine("4 is even."); 
    else Console.WriteLine("3 is odd."); 
 
    // result = ob.isOdd(); // Error, not exposed 
  } 
}

           
          


One interface can inherit another

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/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// One interface can inherit another. 
 
using System; 
 
public interface A { 
  void meth1(); 
  void meth2(); 
} 
 
// B now includes meth1() and meth2() -- it adds meth3(). 
public interface B : A { 
  void meth3(); 
} 
 
// This class must implement all of A and B 
class MyClass : B { 
  public void meth1() { 
    Console.WriteLine("Implement meth1()."); 
  } 
 
  public void meth2() { 
    Console.WriteLine("Implement meth2()."); 
  } 
 
  public void meth3() { 
    Console.WriteLine("Implement meth3()."); 
  } 
} 
 
public class IFExtend { 
  public static void Main() { 
    MyClass ob = new MyClass(); 
 
    ob.meth1(); 
    ob.meth2(); 
    ob.meth3(); 
  } 
}