/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
//
// Members.cs -- Demonstrates access to static and non-static members
//
// Compile this program using the following command line:
// C:>csc Members.cs
//
namespace nsMembers
{
using System;
public class StaticMembers
{
static public void Main ()
{
// Access a static member using the class name.
// You may access a static
// member without creating an instance of the class
Console.WriteLine ("The static member is pi: " + clsClass.pi);
// To access a non-static member, you must create an instance
// of the class
clsClass instance = new clsClass();
// Access a static member using the name of the variable
// containing the
// instance reference
Console.WriteLine ("The instance member is e: " + instance.e);
}
}
class clsClass
{
// Declare a static field. You also could use the const
// keyword instead of static
static public double pi = 3.14159;
// Declare a normal member, which will be created when you
// declare an instance
// of the class
public double e = 2.71828;
}
}
ASP.NET & Csharp (C#)
ASP.NET & Csharp (C#) , Here you can find my posts about .NET c# .
Illustrates the use of static members
/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
Example6_1.cs illustrates the use of static members
*/
// declare the Car class
class Car
{
// declare a static field,
// numberOfCars stores the number of Car objects
private static int numberOfCars = 0;
// define the constructor
public Car()
{
System.Console.WriteLine("Creating a Car object");
numberOfCars++; // increment numberOfCars
}
// define the destructor
~Car()
{
System.Console.WriteLine("Destroying a Car object");
numberOfCars--; // decrement numberOfCars
}
// define a static method that returns numberOfCars
public static int GetNumberOfCars()
{
return numberOfCars;
}
}
public class Example6_1
{
public static void Main()
{
// display numberOfCars
System.Console.WriteLine("Car.GetNumberOfCars() = " +
Car.GetNumberOfCars());
// create a Car object
Car myCar = new Car();
System.Console.WriteLine("Car.GetNumberOfCars() = " +
Car.GetNumberOfCars());
// create another Car object
Car myCar2 = new Car();
System.Console.WriteLine("Car.GetNumberOfCars() = " +
Car.GetNumberOfCars());
}
}
Use a static constructor
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use a static constructor.
using System;
class Cons {
public static int alpha;
public int beta;
// static constructor
static Cons() {
alpha = 99;
Console.WriteLine("Inside static constructor.");
}
// instance constructor
public Cons() {
beta = 100;
Console.WriteLine("Inside instance constructor.");
}
}
public class ConsDemo {
public static void Main() {
Cons ob = new Cons();
Console.WriteLine("Cons.alpha: " + Cons.alpha);
Console.WriteLine("ob.beta: " + ob.beta);
}
}
Use a static class factory
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use a static class factory.
using System;
class MyClass {
int a, b;
// Create a class factory for MyClass.
static public MyClass factory(int i, int j) {
MyClass t = new MyClass();
t.a = i;
t.b = j;
return t; // return an object
}
public void show() {
Console.WriteLine(“a and b: ” + a + ” ” + b);
}
}
public class MakeObjects1 {
public static void Main() {
int i, j;
// generate objects using the factory
for(i=0, j=10; i < 10; i++, j--) {
MyClass ob = MyClass.factory(i, j); // get an object
ob.show();
}
Console.WriteLine();
}
}
[/csharp]
Use a static field to count instances
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use a static field to count instances.
using System;
class CountInst {
static int count = 0;
// increment count when object is created
public CountInst() {
count++;
}
// decrement count when object is destroyed
~CountInst() {
count–;
}
public static int getcount() {
return count;
}
}
public class CountDemo {
public static void Main() {
CountInst ob;
for(int i=0; i < 10; i++) { ob = new CountInst(); Console.WriteLine("Current count: " + CountInst.getcount()); } } } [/csharp]
Can call a non-static method through an object reference from within a static method
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
using System;
public class MyClass {
// non-static method.
void nonStaticMeth() {
Console.WriteLine("Inside nonStaticMeth().");
}
/* Can call a non-static method through an
object reference from within a static method. */
public static void staticMeth(MyClass ob) {
ob.nonStaticMeth(); // this is OK
}
}
Error using static
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
using System;
public class AnotherStaticError {
// non-static method.
void nonStaticMeth() {
Console.WriteLine("Inside nonStaticMeth().");
}
/* Error! Can't directly call a non-static method
from within a static method. */
static void staticMeth() {
nonStaticMeth(); // won't compile
}
}