IDisposable IDisposable IDisposable IDisposable Interface

Definice

Poskytuje mechanismus pro uvolnění 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 prostředku, který 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

K uvolnění nespravovaných prostředků je primárním použitím tohoto rozhraní.The primary use of this interface is to release unmanaged resources. Systému uvolňování paměti automaticky uvolní paměť přidělena spravovaný objekt, pokud tento objekt se už používá.The garbage collector automatically releases the memory allocated to a managed object when that object is no longer used. Není však možné předpovědět, kdy dojde k uvolnění paměti.However, it is not possible to predict when garbage collection will occur. Kromě toho systému uvolňování paměti je vůbec nezná nespravované prostředky, jako jsou popisovače okna, nebo otevřete soubory a proudy.Furthermore, the garbage collector has no knowledge of unmanaged resources such as window handles, or open files and streams.

Použití Dispose metody tohoto rozhraní explicitně uvolnit nespravované prostředky ve spojení s systému uvolňování paměti.Use the Dispose method of this interface to explicitly release unmanaged resources in conjunction with the garbage collector. Příjemce objekt lze tuto metodu volat, pokud objekt je už nepotřebujete.The consumer of an object can call this method when the object is no longer needed.

Varování

Rozbíjející změny, přidejte je IDisposable rozhraní do existující třídy.It is a breaking change to add the IDisposable interface to an existing class. Vzhledem k tomu, že již existující mohou příjemci typu nejde volat metodu Dispose, nemůže být určité, se uvolní nespravované prostředky držené typu.Because pre-existing consumers of your type cannot call Dispose, you cannot be certain that unmanaged resources held by your type will be released.

Protože IDisposable.Dispose implementace je voláno rozhraním příjemce typu, když už nepotřebujete prostředky ve vlastnictví instancí, buď zalamován spravovaný objekt v SafeHandle (Doporučenou alternativou), nebo by měly přepsat 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 rozhraní .NET Framework, kompilátor C++ podporuje deterministického zacházení s prostředky 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, toto rozhraní a Object.Finalize metody se používají, najdete v článku uvolňování a Implementing a Dispose Method témata.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, byste měli volat objektu IDisposable.Dispose implementace po dokončení jeho použití.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 programovacím jazyku můžete tento krok lze provést jedním ze dvou způsobů:Depending on your programming language, you can do this in one of two ways:

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

  • Obalením volání IDisposable.Dispose implementace try / finally bloku.By wrapping the call to the IDisposable.Dispose implementation in a try/finally block.

Poznámka

Dokumentace ke službě pro typy, které implementují IDisposable mějte na paměti tato skutečnost a připomenutí volat jeho Dispose implementace.Documentation for types that implement IDisposable note that fact and include a reminder to call its Dispose implementation.

Příkaz jazyka C# a Visual Basic pomocíThe C# and Visual Basic Using statement

Pokud váš jazyk podporuje konstrukce, jako pomocí příkaz v jazyce C# a použití příkaz v jazyce Visual Basic, můžete místo explicitního volání IDisposable.Dispose sami.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 třídu, která uchovává informace o souboru a počtu slov v ní.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. V době kompilace, implementuje kompilátor jazyka intermediate language (IL) pro try / finally bloku.At compile time, the language compiler implements the intermediate language (IL) for a try/finally block.

Další informace o using příkazu, najdete v článku příkazu Using nebo příkaz using témata.For more information about the using statement, see the Using Statement or using Statement topics.

Blok Try/FinallyThe Try/Finally block

Pokud svůj oblíbený programovací jazyk nepodporuje konstrukce, jako je using příkaz v C# nebo Visual Basic, nebo pokud nechcete používat, můžete volat IDisposable.Dispose implementaci finally bloku try / finally příkazu.If 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 nahradí using blokovat v předchozím příkladu nahraďte try / finally bloku.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 try / finally vzorku naleznete v tématu zkuste... Catch... Příkaz finally, try-finally, nebo try-finally – příkaz.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. Mohou příjemci typu může volat vaše IDisposable.Dispose implementace uvolnění prostředků, pokud instance je už nepotřebujete.The consumers of your type can call your IDisposable.Dispose implementation to free resources when the instance is no longer needed. Zpracovat případy, ve kterých se nebude volat Dispose, měli byste použít třída odvozená z SafeHandle obtékání nespravovaných prostředků, nebo by měly přepsat Object.Finalize metody 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 za účelem je nutné použít libovolné vyčištění po použití nespravovaných prostředků, jako je například uvolnění uvolněním nebo resetováním 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

Definujete základní třídu, která používá nespravované prostředky a, který má, nebo by mohla mít podtřídami, které by mělo být uvolněno, měli byste implementovat IDisposable.Dispose metoda a druhým přetížením Dispose, jak je popsáno v následujících oddíl.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.

Rozhraní IDisposable a hierarchii dědičnostiIDisposable and the inheritance hierarchy

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

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

  • Dispose() Musí volat metoda Dispose(true) a potlačit dokončení výkonu.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 odpovídá vzoru dispose pro základní třídy.The following code fragment reflects the dispose pattern for base classes. Předpokládá, že váš typ nepřepisuje Object.Finalize metody.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 metody vaší třídy by měly 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 použití takto:Subclasses should implement the disposable pattern as follows:

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

  • Finalizační metody poskytují v případě potřeby.They can provide a finalizer if needed. Finalizační metoda musí volat Dispose(false).The finalizer must call Dispose(false).

Všimněte si, že odvozené třídy sami neimplementují IDisposable rozhraní a nemusí obsahovat bez parametrů Dispose metody.Note that derived classes do not themselves implement the IDisposable interface and do not include a parameterless Dispose method. Pouze má přednost před základní třídy Dispose(Boolean) metody.They only override the base class Dispose(Boolean) method.

Následující fragment kódu odpovídá vzoru dispose pro odvozené třídy.The following code fragment reflects the dispose pattern for derived classes. Předpokládá, že váš typ nepřepisuje Object.Finalize metody.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