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PropVariantToUInt64VectorAlloc function

Extracts data from a PROPVARIANT structure into a newly-allocated ULONGLONG vector.

Syntax


HRESULT PropVariantToUInt64VectorAlloc(
  _In_   REFPROPVARIANT propvar,
  _Out_  ULONGLONG **pprgn,
  _Out_  ULONG *pcElem
);

Parameters

propvar [in]

Type: REFPROPVARIANT

Reference to a source PROPVARIANT structure.

pprgn [out]

Type: ULONGLONG**

When this function returns, contains a pointer to a vector of ULONGLONG values extracted from the source PROPVARIANT structure.

pcElem [out]

Type: ULONG*

When this function returns, contains the count of ULONGLONG elements extracted from the source PROPVARIANT structure.

Return value

Type: HRESULT

This function can return one of these values.

Return codeDescription
S_OK

Returns S_OK if successful, or an error value otherwise.

E_INVALIDARG

The PROPVARIANT was not of the appropriate type.

 

Remarks

This helper function is used in places where the calling application expects a PROPVARIANT to hold a vector of ULONGLONG values.

If the source PROPVARIANT has type VT_VECTOR | VT_UI8 or VT_ARRAY | VT_UI8, this function extracts a vector of ULONGLONG values into a newly allocated vector. The calling application is responsible for using CoTaskMemFree to release the vector pointed to by pprgn when it is no longer needed.

Examples

The following example, to be included as part of a larger program, demonstrates how to use PropVariantToUInt64VectorAlloc to access a ULONGLONG vector value in a PROPVARIANT.


// PROPVARIANT propvar;
// Assume the variable propvar is initialized and valid. The application is expecting propvar to contain a vector of ULONGLONG values.
ULONGLONG *prgLongs;
ULONG cElems;
HRESULT hr = PropVariantToUInt64VectorAlloc(propvar, &prgLongs, &cElems);
if (SUCCEEDED(hr))
{
     // prgLongs now points to a vector of cElems ULONGLONGs.
     CoTaskMemFree(prgLongs);
}

Requirements

Minimum supported client

Windows XP with SP2, Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2003 with SP1 [desktop apps only]

Redistributable

Windows Desktop Search (WDS) 3.0

Header

Propvarutil.h

Library

Propsys.lib

DLL

Propsys.dll (version 6.0 or later)

See also

InitPropVariantFromUInt64Vector
PropVariantToUInt64
PropVariantGetUInt64Elem
PropVariantToUInt64Vector
VariantToUInt64Array

 

 

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