CoGetApartmentType function (combaseapi.h)

Article
10/13/2021

Returns the current apartment type and type qualifier.

Syntax

HRESULT CoGetApartmentType(
  [out] APTTYPE          *pAptType,
  [out] APTTYPEQUALIFIER *pAptQualifier
);

Parameters

[out] pAptType

APTTYPE enumeration value that specifies the type of the current apartment.

[out] pAptQualifier

APTTYPEQUALIFIER enumeration value that specifies the type qualifier of the current apartment.

Return value

Returns S_OK if the call succeeded. Otherwise, one of the following error codes is returned.

Return code	Description
E_FAIL	The call could not successfully query the current apartment type and type qualifier.
E_INVALIDARG	An invalid parameter value was supplied to the function. Specifically, one or both of the parameters were set to NULL by the caller.
CO_E_NOTINITIALIZED	CoInitialize or CoInitializeEx was not called on this thread prior to calling CoGetApartmentType.

Remarks

On Windows platforms prior to Windows 7, the following actions must be taken on a thread to query the apartment type:

Call CoGetContextToken to obtain the current context token.
Cast the context token to an IUnknown* pointer.
Call the QueryInterface method on that pointer to obtain the IComThreadingInfo interface.
Call the GetCurrentApartmentType method of the IComThreadingInfo interface to obtain the current apartment type.

In multithreaded scenarios, there is a race condition which can potentially cause an Access Violation within the process when executing the above sequence of operations. The CoGetApartmentType function is recommended as it does not potentially incur the Access Violation.

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2008 R2 [desktop apps \| UWP apps]
Target Platform	Windows
Header	combaseapi.h (include Objbase.h)
Library	Ole32.lib
DLL	Ole32.dll