в 15:31, 26 мая 2010

2010-05-26T15:31:53Z

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==Base destructor==

<source lang="csharp">using System;
public class Base
{
~Base()
{
Console.WriteLine( "Base.~Base()" );
}
}
public class Derived : Base
{
~Derived()
{
Console.WriteLine( "Derived.~Derived()" );
}
}
public class MainClass
{
static void Main()
{
Derived derived = new Derived();
}
}</source>
<pre class=codeResult>Derived.~Derived()
Base.~Base()</pre>

==Demonstrate a destructor.==

<source lang="csharp">using System;

class Destruct {
public int x;

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

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

class DestructDemo {
public static void Main() {
Destruct ob = new Destruct(0);

for(int i=1; i < 100; i++){
Destruct o = new Destruct(i);
}
Console.WriteLine("Done");
}
}</source>
<pre class=codeResult>Done
Destructing 99
Destructing 0
Destructing 98
Destructing 97
Destructing 96
Destructing 95
Destructing 94
Destructing 93
Destructing 92
Destructing 91
Destructing 90
Destructing 89
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Destructing 66
Destructing 65
Destructing 64
Destructing 63
Destructing 62
Destructing 61
Destructing 60
Destructing 59
Destructing 58
Destructing 57
Destructing 56
Destructing 55
Destructing 54
Destructing 53
Destructing 52
Destructing 51
Destructing 50
Destructing 49
Destructing 48
Destructing 47
Destructing 46
Destructing 45
Destructing 44
Destructing 43
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Destructing 41
Destructing 40
Destructing 39
Destructing 38
Destructing 37
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Destructing 30
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Destructing 20
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Destructing 17
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Destructing 7
Destructing 6
Destructing 5
Destructing 4
Destructing 3
Destructing 2
Destructing 1</pre>

==Destructors==

<OL><LI>A destructor method called just prior to an object"s final destruction by the garbage collector.</LI><LI>A destructor can be used to ensure that an object terminates cleanly.</LI><LI>Destructors have this general form:</LI></OL>

<source lang="csharp">~class-name( ) {
// destruction code
}</source>
<p>class-name is the name of the class.</p>

==Illustrates a destructor==

<source lang="csharp">public class Car
{
~Car()
{
System.Console.WriteLine("In ~Car() destructor");
}
}
class MainClass
{
public static void Main()
{
Car myCar = new Car();
System.Console.WriteLine("At the end of Main()");
}
}</source>
<pre class=codeResult>At the end of Main()
In ~Car() destructor</pre>

==Simple Finalize==

<source lang="csharp">using System;
class MyClass
{
~MyClass()
{
Console.WriteLine("Finalizing");
}
}
class MainClass
{
static void Main(string[] args)
{
MyClass fc = new MyClass();
Console.WriteLine("Exiting main");
}
}</source>
<pre class=codeResult>Exiting main
Finalizing</pre>

==Update static field in the deconstructor==

<source lang="csharp">public class MyClass
{
private static int numberOfMyClass = 0;
public MyClass()
{
System.Console.WriteLine("Creating a MyClass object");
numberOfMyClass++;
}
~MyClass()
{
System.Console.WriteLine("Destroying a MyClass object");
numberOfMyClass--; // decrement numberOfMyClass
}
public static int GetNumberOfMyClass()
{
return numberOfMyClass;
}
}

class MainClass
{
public static void Main()
{
System.Console.WriteLine("MyClass.GetNumberOfMyClass() = " + MyClass.GetNumberOfMyClass());
MyClass myMyClass = new MyClass();
System.Console.WriteLine("MyClass.GetNumberOfMyClass() = " + MyClass.GetNumberOfMyClass());
MyClass myMyClass2 = new MyClass();
System.Console.WriteLine("MyClass.GetNumberOfMyClass() = " + MyClass.GetNumberOfMyClass());
}
}</source>
<pre class=codeResult>MyClass.GetNumberOfMyClass() = 0
Creating a MyClass object
MyClass.GetNumberOfMyClass() = 1
Creating a MyClass object
MyClass.GetNumberOfMyClass() = 2
Destroying a MyClass object
Destroying a MyClass object</pre>

==Use destructor and implement IDisposable==

<source lang="csharp">using System;
public class MyClass : IDisposable
{
~MyClass()
{
Console.WriteLine("In destructor");
}

public void Dispose()
{
Console.WriteLine("In Dispose()");
GC.SuppressFinalize(this);
}
}
public class MainClass
{
public static void Main(string[] args)
{
MyClass c1, c2, c3, c4;
c1 = new MyClass();
c2 = new MyClass();
c3 = new MyClass();
c4 = new MyClass();

Console.WriteLine("\n***** Disposing c1 and c3 *****");
c1.Dispose();
c3.Dispose();
}
}</source>
<pre class=codeResult>***** Disposing c1 and c3 *****
In Dispose()
In Dispose()
In destructor
In destructor</pre>

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в 15:31, 26 мая 2010

Admin: 1 версия