ASP.NET & Csharp (C#)

ASP.NET & Csharp (C#) , Here you can find my posts about .NET c# .

Explicitly implement an interface member

Posted on by coder 

   

/*
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

Posted on by coder 

   

/*
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(); 
  } 
}

Add an indexer in an interface

Posted on by coder

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Add an indexer in an interface.

using System;

public interface ISeries {
// an interface property
int next {
get; // return the next number in series
set; // set next number
}

// an interface indexer
int this[int index] {
get; // return the specified number in series
}
}

// Implement ISeries.
class ByTwos : ISeries {
int val;

public ByTwos() {
val = 0;
}

// get or set value using a property
public int next {
get {
val += 2;
return val;
}
set {
val = value;
}
}

// get a value using an index
public int this[int index] {
get {
val = 0;
for(int i=0; i

Use a property in an interface

Posted on by coder

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use a property in an interface.

using System;

public interface ISeries {
// an interface property
int next {
get; // return the next number in series
set; // set next number
}
}

// Implement ISeries.
class ByTwos : ISeries {
int val;

public ByTwos() {
val = 0;
}

// get or set value
public int next {
get {
val += 2;
return val;
}
set {
val = value;
}
}
}

// Demonstrate an interface property.
public class SeriesDemo3 {
public static void Main() {
ByTwos ob = new ByTwos();

// access series through a property
for(int i=0; i < 5; i++) Console.WriteLine("Next value is " + ob.next); Console.WriteLine(" Starting at 21"); ob.next = 21; for(int i=0; i < 5; i++) Console.WriteLine("Next value is " + ob.next); } } [/csharp]

Demonstrate the ByTwos interface 2

Posted on by coder

/*
C#: The Complete Reference
by Herbert Schildt

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

public interface ISeries {
int getNext(); // return next number in series
void reset(); // restart
void setStart(int x); // set starting value
}

// Use ISeries to generate a sequence of even numbers.
class ByTwos : ISeries {
int start;
int val;

public ByTwos() {
start = 0;
val = 0;
}

public int getNext() {
val += 2;
return val;
}

public void reset() {
val = start;
}

public void setStart(int x) {
start = x;
val = start;
}
}

// Use ISeries to implement a series of prime numbers.
class Primes : ISeries {
int start;
int val;

public Primes() {
start = 2;
val = 2;
}

public int getNext() {
int i, j;
bool isprime;

val++;
for(i = val; i < 1000000; i++) { isprime = true; for(j = 2; j < (i/j + 1); j++) { if((i%j)==0) { isprime = false; break; } } if(isprime) { val = i; break; } } return val; } public void reset() { val = start; } public void setStart(int x) { start = x; val = start; } } public class SeriesDemo2 { public static void Main() { ByTwos twoOb = new ByTwos(); Primes primeOb = new Primes(); ISeries ob; for(int i=0; i < 5; i++) { ob = twoOb; Console.WriteLine("Next ByTwos value is " + ob.getNext()); ob = primeOb; Console.WriteLine("Next prime number is " + ob.getNext()); } } } [/csharp]

Demonstrate the ByTwos interface

Posted on by coder

/*
C#: The Complete Reference
by Herbert Schildt

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

public interface ISeries {
int getNext(); // return next number in series
void reset(); // restart
void setStart(int x); // set starting value
}

// Implement ISeries.
class ByTwos : ISeries {
int start;
int val;

public ByTwos() {
start = 0;
val = 0;
}

public int getNext() {
val += 2;
return val;
}

public void reset() {
val = start;
}

public void setStart(int x) {
start = x;
val = start;
}
}

// Demonstrate the ByTwos interface.

public class SeriesDemo {
public static void Main() {
ByTwos ob = new ByTwos();

for(int i=0; i < 5; i++) Console.WriteLine("Next value is " + ob.getNext()); Console.WriteLine(" Resetting"); ob.reset(); for(int i=0; i < 5; i++) Console.WriteLine("Next value is " + ob.getNext()); Console.WriteLine(" Starting at 100"); ob.setStart(100); for(int i=0; i < 5; i++) Console.WriteLine("Next value is " + ob.getNext()); } } [/csharp]

Interface with method name conflicts

Posted on by coder 
   
 
using System;

public delegate void AlarmEvent(IAlarm sender);

public interface IAlarm {
    event AlarmEvent IssueAlarm;
}

abstract class MyStuff : ICloneable {
    public object Clone() {
        return null;
    }
    public void DoStuff() {
    }

}
interface IFoo {
    void DoStuff();
}

interface IBar {
    void DoStuff();
}

interface ITest {
    void DoSomething();
    int DoSomethingElse();
}
class MyClass : IFoo, IBar {
    void IFoo.DoStuff() {
    }
    void IBar.DoStuff() {
    }
}

class MainClass : IComparable {
    public int CompareTo(object other) {
        return -1;
    }
    static int Main(string[] args) {
        MainClass c = new MainClass();
        MainClass c2 = new MainClass();
        if (c.CompareTo(c2) == 0)
            return 0;
        MyClass c3 = new MyClass();
        return 1;
    }
}