IDisposable.Dispose 메서드

정의

관리되지 않는 리소스의 확보, 해제 또는 다시 설정과 관련된 애플리케이션 정의 작업을 수행합니다.Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

public:
 void Dispose();
public void Dispose ();
abstract member Dispose : unit -> unit
Public Sub Dispose ()

예제

다음 예제에서는 구현 하는 방법을 보여 줍니다는 Dispose 메서드.The following example shows how you can implement the Dispose method.

#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.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

설명

닫거나 파일, 스트림 및이 인터페이스를 구현 하는 클래스의 인스턴스를 소유 하는 핸들 등의 관리 되지 않는 리소스를 해제 하려면이 메서드를 사용 합니다.Use this method to close or release unmanaged resources such as files, streams, and handles held by an instance of the class that implements this interface. 규칙에 따라이 메서드는 개체에서 보유 한 리소스 해제와 관련 된 모든 작업에 사용 하거나 개체를 다시 사용할 수 있도록 준비 합니다.By convention, this method is used for all tasks associated with freeing resources held by an object, or preparing an object for reuse.

경고

구현 하는 클래스를 사용 하는 경우는 IDisposable 를 호출 해야 인터페이스를 해당 Dispose 클래스를 사용 하 여 작업을 마쳤으면 구현 합니다.If you are using a class that implements the IDisposable interface, you should call its Dispose implementation when you are finished using the class. 자세한 내용은 "IDisposable을 구현 하는 개체를 사용 하 여" 섹션을 참조 하세요.를 IDisposable 항목입니다.For more information, see the "Using an object that implements IDisposable" section in the IDisposable topic.

이 메서드를 구현 하는 경우에 포함 계층 구조를 통해 호출을 전파 하 여 리소스가 해제 됩니다 모든 보유를 확인 합니다.When implementing this method, ensure that all held resources are freed by propagating the call through the containment hierarchy. 예를 들어 개체는 개체 B를 할당 하 고 개체 B 개체 C에는 다음의 할당 Dispose 구현을 호출 해야 합니다 Dispose B에는 다시 호출 해야 Dispose cFor example, if an object A allocates an object B, and object B allocates an object C, then A's Dispose implementation must call Dispose on B, which must in turn call Dispose on C.

중요

C + + 컴파일러가 리소스의 명확한 삭제를 지원 하며 직접 구현은 허용 하지 않습니다는 Dispose 메서드.The C++ compiler supports deterministic disposal of resources and does not allow direct implementation of the Dispose method.

개체도 호출 해야 합니다는 Dispose 기본 클래스를 구현 하는 경우 기본 클래스의 메서드 IDisposable합니다.An object must also call the Dispose method of its base class if the base class implements IDisposable. 구현에 대 한 자세한 내용은 IDisposable 기본 클래스 및 해당 하위 클래스에는 "IDisposable 및 상속 계층 구조" 섹션을 참조 합니다 IDisposable 항목입니다.For more information about implementing IDisposable on a base class and its subclasses, see the "IDisposable and the inheritance hierarchy" section in the IDisposable topic.

개체의 Dispose 메서드가 두 번 이상 호출 되 면 개체가 첫 번째 이후의 모든 호출을 무시 해야 합니다.If an object's Dispose method is called more than once, the object must ignore all calls after the first one. 개체 해야 하는 경우 예외를 throw 하지 해당 Dispose 메서드가 여러 번 호출 됩니다.The object must not throw an exception if its Dispose method is called multiple times. 인스턴스 메서드 이외의 Dispose throw 할 수는 ObjectDisposedException 리소스가 이미 삭제 됩니다.Instance methods other than Dispose can throw an ObjectDisposedException when resources are already disposed.

사용자가 해제 된 상태와 할당 된 상태를 나타내는 특정 규칙을 사용 하는 리소스 형식이 예상 합니다.Users might expect a resource type to use a particular convention to denote an allocated state versus a freed state. 이 예로 일반적으로 열린 것으로 간주 하거나 닫을 스트림 클래스입니다.An example of this is stream classes, which are traditionally thought of as open or closed. 이러한 규칙에는 클래스의 구현자와 같은 사용자 지정 된 이름의 public 메서드를 구현 하기로 결정할 수 있다 Close는 호출을 Dispose 메서드.The implementer of a class that has such a convention might choose to implement a public method with a customized name, such as Close, that calls the Dispose method.

때문에 합니다 Dispose 메서드를 명시적으로 호출 해야, 관리 되지 않는 리소스 되지 않는 위험은 항상 릴리스를 호출 하는 개체의 소비자 실패 하기 때문에 해당 Dispose 메서드.Because the Dispose method must be called explicitly, there is always a danger that the unmanaged resources will not be released, because the consumer of an object fails to call its Dispose method. 이 문제를 방지 하는 방법은 두 가지:There are two ways to avoid this:

  • 관리 되는 리소스에서 파생 된 개체에 래핑할 System.Runtime.InteropServices.SafeHandle합니다.Wrap the managed resource in an object derived from System.Runtime.InteropServices.SafeHandle. 프로그램 Dispose 하면 구현을 호출 합니다 Dispose 메서드의 System.Runtime.InteropServices.SafeHandle 인스턴스.Your Dispose implementation then calls the Dispose method of the System.Runtime.InteropServices.SafeHandle instances. 자세한 내용은 "SafeHandle 대안" 섹션을 참조 합니다 Object.Finalize 항목입니다.For more information, see "The SafeHandle alternative" section in the Object.Finalize topic.

  • 리소스를 해제 하는 종료자를 구현 하면 Dispose 호출 되지 않습니다.Implement a finalizer to free resources when Dispose is not called. 기본적으로 가비지 수집기는 메모리를 회수 하기 전에 개체의 종료 자가 자동으로 호출 합니다.By default, the garbage collector automatically calls an object's finalizer before reclaiming its memory. 그러나 경우는 Dispose 메서드가 호출 필요한 경우가 아니라면 일반적으로 삭제 된 개체의 종료자를 호출 하는 가비지 수집기입니다.However, if the Dispose method has been called, it is typically unnecessary for the garbage collector to call the disposed object's finalizer. 자동 종료를 방지 하기 위해 Dispose 구현을 호출할 수는 GC.SuppressFinalize 메서드.To prevent automatic finalization, Dispose implementations can call the GC.SuppressFinalize method.

와 같은 관리 되지 않는 리소스를 액세스 하는 개체를 사용 하는 경우는 StreamWriter를 사용 하 여 인스턴스를 만드는 것이 좋습니다는 using 문입니다.When you use an object that accesses unmanaged resources, such as a StreamWriter, a good practice is to create the instance with a using statement. 합니다 using 스트림과 호출에 자동으로 문을 닫습니다 Dispose 사용 하는 코드가 완료 되 면 개체에서.The using statement automatically closes the stream and calls Dispose on the object when the code that is using it has completed. 예를 들어 참조 된 StreamWriter 클래스입니다.For an example, see the StreamWriter class.

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