WeakRef::AsIID Method

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The latest version of this topic can be found at WeakRef::AsIID Method.

Sets the specified ComPtr pointer parameter to represent the specified interface ID.

Syntax

HRESULT AsIID(  
   REFIID riid,  
   _Out_ ComPtr<IInspectable>* ptr  
);

Parameters

riid
An interface ID.

ptr
When this operation completes, an object that represents parameter riid.

Return Value

  • S_OK if this operation succeeds; otherwise, an HRESULT that indicates the reason the operation failed, and ptr is set to nullptr.

  • S_OK if this operation succeeds, but the current WeakRef object has already been released. Parameter ptr is set to nullptr.

  • S_OK if this operation succeeds, but the current WeakRef object is not derived from parameter riid. Parameter ptr is set to nullptr. (For more information, see Remarks.)

Remarks

An error is emitted if parameter riid is not derived from IInspectable. This error supersedes the return value.

The first template is the form that you should use in your code. The second template (not shown here, but declared in the header file) is an internal, helper specialization that supports C++ language features such as the auto type deduction keyword.

Starting in the Windows 10 SDK, this method does not set the WeakRef instance to nullptr if the weak reference could not be obtained, so you should avoid error-checking code that checks the WeakRef for nullptr. Instead, check ptr for nullptr.

Requirements

Header: client.h

Namespace: Microsoft::WRL

See Also

WeakRef Class