IDisposable IDisposable IDisposable IDisposable Interface

Definice

Poskytuje mechanismus pro uvolňování nespravovaných prostředků.Provides a mechanism for releasing unmanaged resources.

public interface class IDisposable
[System.Runtime.InteropServices.ComVisible(true)]
public interface IDisposable
type IDisposable = interface
Public Interface IDisposable
Odvozené
Atributy

Příklady

Následující příklad ukazuje, jak vytvořit třídu prostředků, která implementuje IDisposable rozhraní.The following example demonstrates how to create a resource class that implements the IDisposable interface.

#using <System.dll>
#using <System.Windows.Forms.dll>

using namespace System;
using namespace System::ComponentModel;
using namespace System::Windows::Forms;

// The following example demonstrates how to create a class that 
// implements the IDisposable interface and the IDisposable.Dispose
// method with finalization to clean up unmanaged resources. 
//
public ref class MyResource: public IDisposable
{
private:

   // Pointer to an external unmanaged resource.
   IntPtr handle;

   // A managed resource this class uses.
   Component^ component;

   // Track whether Dispose has been called.
   bool disposed;

public:
   // The class constructor.
   MyResource( IntPtr handle, Component^ component )
   {
      this->handle = handle;
      this->component = component;
      disposed = false;
   }

   // This method is called if the user explicitly disposes of the
   // object (by calling the Dispose method in other managed languages, 
   // or the destructor in C++). The compiler emits as a call to 
   // GC::SuppressFinalize( this ) for you, so there is no need to 
   // call it here.
   ~MyResource() 
   {
      // Dispose of managed resources.
      component->~Component();

      // Call C++ finalizer to clean up unmanaged resources.
      this->!MyResource();

      // Mark the class as disposed. This flag allows you to throw an
      // exception if a disposed object is accessed.
      disposed = true;
   }

   // Use interop to call the method necessary to clean up the 
   // unmanaged resource.
   //
   [System::Runtime::InteropServices::DllImport("Kernel32")]
   static Boolean CloseHandle( IntPtr handle );

   // The C++ finalizer destructor ensures that unmanaged resources get
   // released if the user releases the object without explicitly 
   // disposing of it.
   //
   !MyResource()
   {      
      // Call the appropriate methods to clean up unmanaged 
      // resources here. If disposing is false when Dispose(bool,
      // disposing) is called, only the following code is executed.
      CloseHandle( handle );
      handle = IntPtr::Zero;
   }

};

void main()
{
   // Insert code here to create and use the MyResource object.
   MyResource^ mr = gcnew MyResource((IntPtr) 42, (Component^) gcnew Button());
   mr->~MyResource();
}
using System;
using System.ComponentModel;

// The following example demonstrates how to create
// a resource class that implements the IDisposable interface
// and the IDisposable.Dispose method.

public class DisposeExample
{
    // A base class that implements IDisposable.
    // By implementing IDisposable, you are announcing that
    // instances of this type allocate scarce resources.
    public class MyResource: IDisposable
    {
        // Pointer to an external unmanaged resource.
        private IntPtr handle;
        // Other managed resource this class uses.
        private Component component = new Component();
        // Track whether Dispose has been called.
        private bool disposed = false;

        // The class constructor.
        public MyResource(IntPtr handle)
        {
            this.handle = handle;
        }

        // Implement IDisposable.
        // Do not make this method virtual.
        // A derived class should not be able to override this method.
        public void Dispose()
        {
            Dispose(true);
            // This object will be cleaned up by the Dispose method.
            // Therefore, you should call GC.SupressFinalize to
            // take this object off the finalization queue
            // and prevent finalization code for this object
            // from executing a second time.
            GC.SuppressFinalize(this);
        }

        // Dispose(bool disposing) executes in two distinct scenarios.
        // If disposing equals true, the method has been called directly
        // or indirectly by a user's code. Managed and unmanaged resources
        // can be disposed.
        // If disposing equals false, the method has been called by the
        // runtime from inside the finalizer and you should not reference
        // other objects. Only unmanaged resources can be disposed.
        protected virtual void Dispose(bool disposing)
        {
            // Check to see if Dispose has already been called.
            if(!this.disposed)
            {
                // If disposing equals true, dispose all managed
                // and unmanaged resources.
                if(disposing)
                {
                    // Dispose managed resources.
                    component.Dispose();
                }

                // Call the appropriate methods to clean up
                // unmanaged resources here.
                // If disposing is false,
                // only the following code is executed.
                CloseHandle(handle);
                handle = IntPtr.Zero;

                // Note disposing has been done.
                disposed = true;

            }
        }

        // Use interop to call the method necessary
        // to clean up the unmanaged resource.
        [System.Runtime.InteropServices.DllImport("Kernel32")]
        private extern static Boolean CloseHandle(IntPtr handle);

        // Use C# destructor syntax for finalization code.
        // This destructor will run only if the Dispose method
        // does not get called.
        // It gives your base class the opportunity to finalize.
        // Do not provide destructors in types derived from this class.
        ~MyResource()
        {
            // Do not re-create Dispose clean-up code here.
            // Calling Dispose(false) is optimal in terms of
            // readability and maintainability.
            Dispose(false);
        }
    }
    public static void Main()
    {
        // Insert code here to create
        // and use the MyResource object.
    }
}
Imports System
Imports System.ComponentModel

' The following example demonstrates how to create
' a resource class that implements the IDisposable interface
' and the IDisposable.Dispose method.
Public Class DisposeExample

   ' A class that implements IDisposable.
   ' By implementing IDisposable, you are announcing that 
   ' instances of this type allocate scarce resources.
   Public Class MyResource
      Implements IDisposable
      ' Pointer to an external unmanaged resource.
      Private handle As IntPtr
      ' Other managed resource this class uses.
      Private component As component
      ' Track whether Dispose has been called.
      Private disposed As Boolean = False

      ' The class constructor.
      Public Sub New(ByVal handle As IntPtr)
         Me.handle = handle
      End Sub

      ' Implement IDisposable.
      ' Do not make this method virtual.
      ' A derived class should not be able to override this method.
      Public Overloads Sub Dispose() Implements IDisposable.Dispose
         Dispose(True)
         ' This object will be cleaned up by the Dispose method.
         ' Therefore, you should call GC.SupressFinalize to
         ' take this object off the finalization queue 
         ' and prevent finalization code for this object
         ' from executing a second time.
         GC.SuppressFinalize(Me)
      End Sub

      ' Dispose(bool disposing) executes in two distinct scenarios.
      ' If disposing equals true, the method has been called directly
      ' or indirectly by a user's code. Managed and unmanaged resources
      ' can be disposed.
      ' If disposing equals false, the method has been called by the 
      ' runtime from inside the finalizer and you should not reference 
      ' other objects. Only unmanaged resources can be disposed.
      Protected Overridable Overloads Sub Dispose(ByVal disposing As Boolean)
         ' Check to see if Dispose has already been called.
         If Not Me.disposed Then
            ' If disposing equals true, dispose all managed 
            ' and unmanaged resources.
            If disposing Then
               ' Dispose managed resources.
               component.Dispose()
            End If

            ' Call the appropriate methods to clean up 
            ' unmanaged resources here.
            ' If disposing is false, 
            ' only the following code is executed.
            CloseHandle(handle)
            handle = IntPtr.Zero

            ' Note disposing has been done.
            disposed = True

         End If
      End Sub

      ' Use interop to call the method necessary  
      ' to clean up the unmanaged resource.
      <System.Runtime.InteropServices.DllImport("Kernel32")> _
      Private Shared Function CloseHandle(ByVal handle As IntPtr) As [Boolean]
      End Function

      ' This finalizer will run only if the Dispose method 
      ' does not get called.
      ' It gives your base class the opportunity to finalize.
      ' Do not provide finalize methods in types derived from this class.
      Protected Overrides Sub Finalize()
         ' Do not re-create Dispose clean-up code here.
         ' Calling Dispose(false) is optimal in terms of
         ' readability and maintainability.
         Dispose(False)
         MyBase.Finalize()
      End Sub
   End Class

   Public Shared Sub Main()
      ' Insert code here to create
      ' and use the MyResource object.
   End Sub

End Class

Poznámky

Primárním použitím tohoto rozhraní je uvolnění nespravovaných prostředků.The primary use of this interface is to release unmanaged resources. Systém uvolňování paměti automaticky uvolní paměť přidělenou spravovanému objektu, když tento objekt již není používán.The garbage collector automatically releases the memory allocated to a managed object when that object is no longer used. Při uvolňování paměti ale není možné předpovědět.However, it is not possible to predict when garbage collection will occur. Kromě toho systém uvolňování paměti nemá žádné znalosti o nespravovaných zdrojích, jako jsou například obslužné rutiny oken nebo otevřené soubory a datové proudy.Furthermore, the garbage collector has no knowledge of unmanaged resources such as window handles, or open files and streams.

Dispose Použijte metodu tohoto rozhraní k explicitnímu uvolnění nespravovaných prostředků ve spojení se systémem uvolňování paměti.Use the Dispose method of this interface to explicitly release unmanaged resources in conjunction with the garbage collector. Příjemce objektu může zavolat tuto metodu, pokud již objekt není potřeba.The consumer of an object can call this method when the object is no longer needed.

Varování

Jedná se o zásadní změnu pro přidání IDisposable rozhraní do existující třídy.It is a breaking change to add the IDisposable interface to an existing class. Vzhledem k tomu, že již stávající spotřebitelé vašeho typu Disposenemohou volat, nemůžete být jisti, že se uvolní nespravované prostředky držené vaším typem.Because pre-existing consumers of your type cannot call Dispose, you cannot be certain that unmanaged resources held by your type will be released.

Vzhledem k tomu, že SafeHandle implementacejevolánapříjemcemtypu,kdyžprostředkyvlastněnéinstancíjižnepotřebujete,mělibystebuďzabalitspravovanýobjektv(Doporučenéalternativy),nebopřepsatIDisposable.Dispose Object.Finalizepro uvolnění nespravovaných prostředků v případě, že uživatel zapomene zavolat Dispose.Because the IDisposable.Dispose implementation is called by the consumer of a type when the resources owned by an instance are no longer needed, you should either wrap the managed object in a SafeHandle (the recommended alternative), or you should override Object.Finalize to free unmanaged resources in the event that the consumer forgets to call Dispose.

Důležité

V .NET Framework C++ kompilátor podporuje deterministické odstraňování prostředků a neumožňuje přímou implementaci Dispose metody.In the .NET Framework, the C++ compiler supports deterministic disposal of resources and does not allow direct implementation of the Dispose method.

Podrobné informace o tom, jak se toto rozhraní a Object.Finalize metoda používají, najdete v tématech uvolňování paměti a implementace metody Dispose .For a detailed discussion about how this interface and the Object.Finalize method are used, see the Garbage Collection and Implementing a Dispose Method topics.

Použití objektu, který implementuje rozhraní IDisposableUsing an object that implements IDisposable

Pokud vaše aplikace jednoduše používá objekt, který implementuje IDisposable rozhraní, měli byste zavolat IDisposable.Dispose implementaci objektu, až ho budete používat.If your app simply uses an object that implements the IDisposable interface, you should call the object's IDisposable.Dispose implementation when you are finished using it. V závislosti na vašem programovacím jazyce můžete to provést jedním ze dvou způsobů:Depending on your programming language, you can do this in one of two ways:

  • Pomocí konstrukce jazyka, jako je using například příkaz v C# a Visual Basic.By using a language construct such as the using statement in C# and Visual Basic.

  • Zabalením volání IDisposable.Dispose implementace try / v bloku.finallyBy wrapping the call to the IDisposable.Dispose implementation in a try/finally block.

Poznámka

Dokumentace pro typy, které IDisposable implementují tuto skutečnost a obsahují připomenutí pro volání své Dispose implementace.Documentation for types that implement IDisposable note that fact and include a reminder to call its Dispose implementation.

Příkaz C# and Visual Basic usingThe C# and Visual Basic Using statement

Pokud váš jazyk podporuje konstrukce, jako je například příkaz using v C# a příkaz using v Visual Basic, můžete jej použít místo explicitního volání IDisposable.Dispose .If your language supports a construct such as the using statement in C# and the Using statement in Visual Basic, you can use it instead of explicitly calling IDisposable.Dispose yourself. Následující příklad používá tento přístup při definování WordCount třídy, která zachovává informace o souboru a počtu slov v něm.The following example uses this approach in defining a WordCount class that preserves information about a file and the number of words in it.

using System;
using System.IO;
using System.Text.RegularExpressions;

public class WordCount
{
   private String filename = String.Empty;
   private int nWords = 0;
   private String pattern = @"\b\w+\b"; 

   public WordCount(string filename)
   {
      if (! File.Exists(filename))
         throw new FileNotFoundException("The file does not exist.");
      
      this.filename = filename;
      string txt = String.Empty;
      using (StreamReader sr = new StreamReader(filename)) {
         txt = sr.ReadToEnd();
      }
      nWords = Regex.Matches(txt, pattern).Count;
   }
   
   public string FullName
   { get { return filename; } }
   
   public string Name
   { get { return Path.GetFileName(filename); } }
   
   public int Count 
   { get { return nWords; } }
}   
Imports System.IO
Imports System.Text.RegularExpressions

Public Class WordCount
   Private filename As String
   Private nWords As Integer
   Private pattern As String = "\b\w+\b" 

   Public Sub New(filename As String)
      If Not File.Exists(filename) Then
         Throw New FileNotFoundException("The file does not exist.")
      End If   
      
      Me.filename = filename
      Dim txt As String = String.Empty
      Using sr As New StreamReader(filename)
         txt = sr.ReadToEnd()
      End Using
      nWords = Regex.Matches(txt, pattern).Count
   End Sub
   
   Public ReadOnly Property FullName As String
      Get
         Return filename
      End Get   
   End Property
   
   Public ReadOnly Property Name As String
      Get
         Return Path.GetFileName(filename)
      End Get   
   End Property
   
   Public ReadOnly Property Count As Integer
      Get
         Return nWords
      End Get
   End Property
End Class

using Příkaz je ve skutečnosti syntaktické pohodlí.The using statement is actually a syntactic convenience. Kompilátor jazyka v době kompilace implementuje převodní jazyk (IL) pro try / finally blok.At compile time, the language compiler implements the intermediate language (IL) for a try/finally block.

Další informace o using příkazu naleznete v tématech using nebo using Statement .For more information about the using statement, see the Using Statement or using Statement topics.

Blok try/finallyThe Try/Finally block

Pokud váš programovací jazyk nepodporuje using konstrukci, jako je příkaz v C# nebo Visual Basic, nebo pokud nechcete použít, můžete volat IDisposable.Dispose implementaci z bloku try finally /příkaz. finallyIf your programming language does not support a construct like the using statement in C# or Visual Basic, or if you prefer not to use it, you can call the IDisposable.Dispose implementation from the finally block of a try/finally statement. Následující příklad nahrazuje using blok v předchozím / příkladu try finally blokem.The following example replaces the using block in the previous example with a try/finally block.

using System;
using System.IO;
using System.Text.RegularExpressions;

public class WordCount
{
   private String filename = String.Empty;
   private int nWords = 0;
   private String pattern = @"\b\w+\b"; 

   public WordCount(string filename)
   {
      if (! File.Exists(filename))
         throw new FileNotFoundException("The file does not exist.");
      
      this.filename = filename;
      string txt = String.Empty;
      StreamReader sr = null;
      try {
         sr = new StreamReader(filename);
         txt = sr.ReadToEnd();
      }
      finally {
         if (sr != null) sr.Dispose();     
      }
      nWords = Regex.Matches(txt, pattern).Count;
   }
   
   public string FullName
   { get { return filename; } }
   
   public string Name
   { get { return Path.GetFileName(filename); } }
   
   public int Count 
   { get { return nWords; } }
}   
Imports System.IO
Imports System.Text.RegularExpressions

Public Class WordCount
   Private filename As String
   Private nWords As Integer
   Private pattern As String = "\b\w+\b" 

   Public Sub New(filename As String)
      If Not File.Exists(filename) Then
         Throw New FileNotFoundException("The file does not exist.")
      End If   
      
      Me.filename = filename
      Dim txt As String = String.Empty
      Dim sr As StreamReader = Nothing
      Try
         sr = New StreamReader(filename)
         txt = sr.ReadToEnd()
      Finally
         If sr IsNot Nothing Then sr.Dispose() 
      End Try
      nWords = Regex.Matches(txt, pattern).Count
   End Sub
   
   Public ReadOnly Property FullName As String
      Get
         Return filename
      End Get   
   End Property
   
   Public ReadOnly Property Name As String
      Get
         Return Path.GetFileName(filename)
      End Get   
   End Property
   
   Public ReadOnly Property Count As Integer
      Get
         Return nWords
      End Get
   End Property
End Class

Další informace o tomto try / finally vzoru naleznete v tématu Try... Zachytit... Finally– příkaz try-finallynebo try-finally.For more information about the try/finally pattern, see Try...Catch...Finally Statement, try-finally, or try-finally Statement.

Implementace rozhraní IDisposableImplementing IDisposable

Měli byste implementovat IDisposable pouze v případě, že váš typ používá nespravované prostředky přímo.You should implement IDisposable only if your type uses unmanaged resources directly. Příjemci vašeho typu mohou zavolat vaší IDisposable.Dispose implementaci na bezplatné prostředky, pokud již instance není potřebná.The consumers of your type can call your IDisposable.Dispose implementation to free resources when the instance is no longer needed. Chcete-li zpracovat případy, ve kterých nevolají volání Dispose, měli byste buď použít třídu odvozenou z SafeHandle pro zabalení nespravovaných prostředků, Object.Finalize nebo přepsat metodu pro typ odkazu.To handle cases in which they fail to call Dispose, you should either use a class derived from SafeHandle to wrap the unmanaged resources, or you should override the Object.Finalize method for a reference type. V obou případech použijete Dispose metodu k provedení jakéhokoli vyčištění po použití nespravovaných prostředků, jako je uvolnění, uvolnění nebo obnovení nespravovaných prostředků.In either case, you use the Dispose method to perform whatever cleanup is necessary after using the unmanaged resources, such as freeing, releasing, or resetting the unmanaged resources.

Důležité

Pokud definujete základní třídu, která používá nespravované prostředky a má nebo má pravděpodobně mít, podtřídy, které by měly být uvolněny, měli byste implementovat IDisposable.Dispose metodu a poskytnout druhé Disposepřetížení, jak je popsáno v následující části. section.If you are defining a base class that uses unmanaged resources and that either has, or is likely to have, subclasses that should be disposed, you should implement the IDisposable.Dispose method and provide a second overload of Dispose, as discussed in the next section.

IDisposable a Hierarchie dědičnostiIDisposable and the inheritance hierarchy

Základní třída s podtřídami, které by měly být na jedno IDisposable použití, musí implementovat následujícím způsobem.A base class with subclasses that should be disposable must implement IDisposable as follows. Tento model byste měli použít vždy, když IDisposable implementujete u libovolného typu sealed ,NotInheritable který není (v Visual Basic).You should use this pattern whenever you implement IDisposable on any type that isn't sealed (NotInheritable in Visual Basic).

  • Měla by poskytovat jednu veřejnou, nevirtuální Dispose() metodu a chráněnou virtuální Dispose(Boolean disposing) metodu.It should provide one public, non-virtual Dispose() method and a protected virtual Dispose(Boolean disposing) method.

  • Metoda musí volat Dispose(true) a měla by potlačit finalizaci pro výkon. Dispose()The Dispose() method must call Dispose(true) and should suppress finalization for performance.

  • Základní typ by neměl obsahovat žádné finalizační metody.The base type should not include any finalizers.

Následující fragment kódu odráží vzor Dispose pro základní třídy.The following code fragment reflects the dispose pattern for base classes. Předpokládá, že váš typ nepřepisuje Object.Finalize metodu.It assumes that your type does not override the Object.Finalize method.

using Microsoft.Win32.SafeHandles;
using System;
using System.Runtime.InteropServices;

class BaseClass : IDisposable
{
   // Flag: Has Dispose already been called?
   bool disposed = false;
   // Instantiate a SafeHandle instance.
   SafeHandle handle = new SafeFileHandle(IntPtr.Zero, true);
   
   // Public implementation of Dispose pattern callable by consumers.
   public void Dispose()
   { 
      Dispose(true);
      GC.SuppressFinalize(this);           
   }
   
   // Protected implementation of Dispose pattern.
   protected virtual void Dispose(bool disposing)
   {
      if (disposed)
         return; 
      
      if (disposing) {
         handle.Dispose();
         // Free any other managed objects here.
         //
      }
      
      disposed = true;
   }
}
Imports Microsoft.Win32.SafeHandles
Imports System.Runtime.InteropServices

Class BaseClass : Implements IDisposable
   ' Flag: Has Dispose already been called?
   Dim disposed As Boolean = False
   ' Instantiate a SafeHandle instance.
   Dim handle As SafeHandle = New SafeFileHandle(IntPtr.Zero, True)

   ' Public implementation of Dispose pattern callable by consumers.
   Public Sub Dispose() _
              Implements IDisposable.Dispose
      Dispose(True)
      GC.SuppressFinalize(Me)           
   End Sub
   
   ' Protected implementation of Dispose pattern.
   Protected Overridable Sub Dispose(disposing As Boolean)
      If disposed Then Return
      
      If disposing Then
         handle.Dispose()
         ' Free any other managed objects here.
         '
      End If
      
      disposed = True
   End Sub
End Class

Pokud přepíšete Object.Finalize metodu, vaše třída by měla implementovat následující vzor.If you do override the Object.Finalize method, your class should implement the following pattern.

using System;

class BaseClass : IDisposable
{
   // Flag: Has Dispose already been called?
   bool disposed = false;
   
   // Public implementation of Dispose pattern callable by consumers.
   public void Dispose()
   { 
      Dispose(true);
      GC.SuppressFinalize(this);           
   }
   
   // Protected implementation of Dispose pattern.
   protected virtual void Dispose(bool disposing)
   {
      if (disposed)
         return; 
      
      if (disposing) {
         // Free any other managed objects here.
         //
      }
      
      // Free any unmanaged objects here.
      //
      disposed = true;
   }

   ~BaseClass()
   {
      Dispose(false);
   }
}
Class BaseClass : Implements IDisposable
   ' Flag: Has Dispose already been called?
   Dim disposed As Boolean = False
   
   ' Public implementation of Dispose pattern callable by consumers.
   Public Sub Dispose() _
              Implements IDisposable.Dispose
      Dispose(True)
      GC.SuppressFinalize(Me)           
   End Sub
   
   ' Protected implementation of Dispose pattern.
   Protected Overridable Sub Dispose(disposing As Boolean)
      If disposed Then Return
      
      If disposing Then
         ' Free any other managed objects here.
         '
      End If
      
      ' Free any unmanaged objects here.
      '
      disposed = True
   End Sub

   Protected Overrides Sub Finalize()
      Dispose(False)      
   End Sub
End Class

Podtřídy by měly implementovat vzor na jedno, jak je znázorněno níže:Subclasses should implement the disposable pattern as follows:

  • Musí přepsat Dispose(Boolean) a volat implementaci základní třídy Dispose(Boolean) .They must override Dispose(Boolean) and call the base class Dispose(Boolean) implementation.

  • V případě potřeby můžou poskytnout finalizační metodu.They can provide a finalizer if needed. Finalizační metoda musí volat Dispose(false).The finalizer must call Dispose(false).

Všimněte si, že odvozené třídy samy neimplementují IDisposable rozhraní a nezahrnují Dispose metodu bez parametrů.Note that derived classes do not themselves implement the IDisposable interface and do not include a parameterless Dispose method. Přepíší pouze metodu základní třídy Dispose(Boolean) .They only override the base class Dispose(Boolean) method.

Následující fragment kódu odráží vzor Dispose pro odvozené třídy.The following code fragment reflects the dispose pattern for derived classes. Předpokládá, že váš typ nepřepisuje Object.Finalize metodu.It assumes that your type does not override the Object.Finalize method.

using Microsoft.Win32.SafeHandles;
using System;
using System.Runtime.InteropServices;

class DerivedClass : BaseClass
{
   // Flag: Has Dispose already been called?
   bool disposed = false;
   // Instantiate a SafeHandle instance.
   SafeHandle handle = new SafeFileHandle(IntPtr.Zero, true);

   // Protected implementation of Dispose pattern.
   protected override void Dispose(bool disposing)
   {
      if (disposed)
         return; 
      
      if (disposing) {
         handle.Dispose();
         // Free any other managed objects here.
         //
      }
      
      // Free any unmanaged objects here.
      //

      disposed = true;
      // Call base class implementation.
      base.Dispose(disposing);
   }
}
Imports Microsoft.Win32.SafeHandles
Imports System.Runtime.InteropServices

Class DerivedClass : Inherits BaseClass 
   ' Flag: Has Dispose already been called?
   Dim disposed As Boolean = False
   ' Instantiate a SafeHandle instance.
   Dim handle As SafeHandle = New SafeFileHandle(IntPtr.Zero, True)

   ' Protected implementation of Dispose pattern.
   Protected Overrides Sub Dispose(disposing As Boolean)
      If disposed Then Return
      
      If disposing Then
         handle.Dispose()
         ' Free any other managed objects here.
         '
      End If
      
      ' Free any unmanaged objects here.
      '
      disposed = True
      
      ' Call base class implementation.
      MyBase.Dispose(disposing)
   End Sub
End Class

Metody

Dispose() Dispose() Dispose() Dispose()

Provádí úkoly definované aplikací, které jsou spojeny s uvolněním nebo obnovením nespravovaných prostředků.Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

Platí pro

Viz také