в 15:31, 26 мая 2010

2010-05-26T15:31:18Z

Admin: 1 версия

2010-05-26T11:39:09Z

1 версия

Новая страница

==Demonstrate a destructor==

<source lang="csharp">
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Demonstrate a destructor.

using System;

class Destruct {
public int x;

public Destruct(int i) {
x = i;
}

// called when object is recycled
~Destruct() {
Console.WriteLine("Destructing " + x);
}

// generates an object that is immediately destroyed
public void generator(int i) {
Destruct o = new Destruct(i);
}

}

public class DestructDemo1 {
public static void Main() {
int count;

Destruct ob = new Destruct(0);

/* Now, generate a large number of objects. At
some point, garbage collection will occur.
Note: you might need to increase the number
of objects generated in order to force
garbage collection. */

for(count=1; count < 100000; count++)
ob.generator(count);

Console.WriteLine("Done");
}
}

</source>

==Finalizable Disposable Class==

<source lang="csharp">
using System;
using System.Collections.Generic;
using System.Text;
class Program {
static void Main(string[] args) {
using (MyResourceWrapper rw = new MyResourceWrapper()) {
}
MyResourceWrapper rw2 = new MyResourceWrapper();
for (int i = 0; i < 10; i++)
rw2.Dispose();
}
}
public class MyResourceWrapper : IDisposable {
public void Dispose() {
Console.WriteLine("In Dispose() method!");
}
}
</source>

==force the GC to invoke Finalize() for finalizable objects created in this AppDomain.==

<source lang="csharp">
using System;
using System.Collections.Generic;
using System.Text;
public class MyResourceWrapper {
~MyResourceWrapper() {
Console.Beep();
}
}
class Program {
static void Main(string[] args) {
MyResourceWrapper rw = new MyResourceWrapper();
}
}
</source>

==Illustrates a destructor==

<source lang="csharp">
/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
Example5_14.cs illustrates a destructor
*/

// declare the Car class
class Car
{
// define the destructor
~Car()
{
System.Console.WriteLine("In ~Car() destructor");
// do any cleaning up here
}
}

public class Example5_14
{
public static void Main()
{
// create a Car object
Car myCar = new Car();
System.Console.WriteLine("At the end of Main()");
}
}

</source>

==Shows that stack unwinding in C# does not necessarily call destructors==

<source lang="csharp">
/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
// Unwind.cs -- Shows that stack unwinding in C# does not necessarily call
// destructors.
// Compile this program with the following command line:
// C:>csc Unwind.cs
//
namespace nsStack
{
using System;
using System.IO;

public class Unwind
{
static public void Main ()
{
Unwind main = new Unwind();
// Set up the try ... catch block
try
{
main.TestStack ();
}
catch (FileNotFoundException e)
{
// Show the contents of the Message string in each class object
if (clsFirst.Message == null)
Console.WriteLine ("First message is null");
else
Console.WriteLine (clsFirst.Message);
if (clsFirst.Message == null)
Console.WriteLine ("Second message is null");
else
Console.WriteLine (clsSecond.Message);
if (clsFirst.Message == null)
Console.WriteLine ("Third message is null");
else
Console.WriteLine (clsThird.Message);
// Show the exception object message
Console.WriteLine (e.Message);
}
}
void TestStack ()
{
// Create a new clsFirst object and call a method in it
clsFirst first = new clsFirst ();
first.FirstFunc();
}
}
class clsFirst
{
~clsFirst ()
{
Message = "clsFirst destructor called";
}
static public string Message = null;
public void FirstFunc()
{
// Create a new clsSecond object and call a method in it
clsSecond second = new clsSecond();
second.SecondFunc ();
}
}
class clsSecond {
~clsSecond () {
Message = "clsSecond destructor called";
}
static public string Message = null;
public void SecondFunc()
{
// Create a new clsThird object and call a method in it
clsThird third = new clsThird();
third.ThirdFunc ();
}
}
class clsThird
{
~clsThird () {
Message = "clsThird destructor called";
}
static public string Message = null;
public void ThirdFunc() {
ThrowException ();
}
// By the time the program gets here, it is five method calls deep.
// Throw an exception to force a stack unwind.
private void ThrowException () {
throw (new FileNotFoundException ());
}
}
}

</source>

==the destructors are called bottom-up, which confirms the sequencing of destructors.==

<source lang="csharp">
using System;

public class Starter {
public static void Main() {
XClass obj = new XClass();
}
}
public class MyClass {
~MyClass() {
Console.WriteLine("MyClass destructor");
}
}
public class YClass : MyClass {
~YClass() {
Console.WriteLine("YClass destructor");
}
}
public class XClass : YClass {
~XClass() {
Console.WriteLine("XClass destructor");
}
}
</source>

← Предыдущая	Версия 15:31, 26 мая 2010
(нет различий)

Csharp/C Sharp/Class Interface/Destructor - История изменений

в 15:31, 26 мая 2010

Admin: 1 версия