PropVariantToUInt64VectorAlloc function (propvarutil.h)

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

Syntax

PSSTDAPI PropVariantToUInt64VectorAlloc(
  [in]  REFPROPVARIANT propvar,
  [out] ULONGLONG      **pprgn,
  [out] ULONG          *pcElem
);

Parameters

[in] propvar

Type: REFPROPVARIANT

Reference to a source PROPVARIANT structure.

[out] pprgn

Type: ULONGLONG**

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

[out] pcElem

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.

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

See also

InitPropVariantFromUInt64Vector

PropVariantGetUInt64Elem

PropVariantToUInt64

PropVariantToUInt64Vector

VariantToUInt64Array