IClosable interface

Defines a method to release allocated resources.

.NET:  This interface appears as System.IDisposable.

C++/CX:  This interface appears as Platform::IDisposable.


public interface class IClosable


The IClosable interface inherits from the IUnknown interface. IClosable also has these types of members:


The IClosable interface has these methods. It also inherits methods from the Object class.

Close Releases system resources that are exposed by a Windows Runtime object.



This interface is projected to a different interface for all possible languages, so it should be considered as an infrastructure piece that the overall Windows Runtime programming experience uses as an implementation detail. There are no typical app development scenarios that rely on implementing or using the IClosable interface directly, unless you're using WRL.

Notes to implementers

When programming with .NET, this interface is hidden and is replaced by the System.IDisposable interface.

If you are defining a runtime class in C++/CX and define a destructor, don't implement IClosable. There's already compiler-based behavior that implements a cleanup behavior for you, (as Platform::IDisposable) and your explicit implementation will clash with the built-in behavior. For more info, see the "Destructors" section of Ref classes and structs (C++/CX).

The purpose of this interface (as exposed by the languages) is so that Windows Runtime objects can wrap and dispose of exclusive system or device/hardware resources appropriately, such as file handles and network sockets. You do not implement this interface for Windows Runtime objects that wrap shared system resources, such as memory and shareable devices.

Notes to callers

Close methods aren't callable through Visual C++ component extensions (C++/CX) on Windows Runtime class instances. Instead, C++/CX code for runtime classes that wants to explicitly clean up a reference should call the destructor or set the last reference to null.

The scenario for Platform::IDisposable/System.IDisposable is to support language-specific syntax that isolates references, such as the using() syntax in C#, or scoping behavior for reference counting in C++. Actually casting to the interfaces or invoking its methods from any app code in any language is rarely necessary.

Requirements (Windows 10 device family)

Device family

Universal, introduced version 10.0.10240.0

API contract

Windows.Foundation.FoundationContract, introduced version 1.0





Requirements (Windows 8.x and Windows Phone 8.x)

Minimum supported client

Windows 8

Minimum supported server

Windows Server 2012

Minimum supported phone

Windows Phone 8







See also




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