PropVariantToInt32VectorAlloc function (propvarutil.h)

Extracts data from a PROPVARIANT structure into a newly-allocated Int32 vector.

Syntax

PSSTDAPI PropVariantToInt32VectorAlloc(
  [in]  REFPROPVARIANT propvar,
  [out] LONG           **pprgn,
  [out] ULONG          *pcElem
);

Parameters

[in] propvar

Type: REFPROPVARIANT

Reference to a source PROPVARIANT structure.

[out] pprgn

Type: LONG**

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

[out] pcElem

Type: ULONG*

When this function returns, contains the count of LONG 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 an Int32 vector value.

If the source PROPVARIANT has type VT_VECTOR | VT_I4 or VT_ARRAY | VT_I4, this function extracts a vector of LONG 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 PropVariantToInt32VectorAlloc to access an LONG 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 LONG values.
LONG *prgLongs;
ULONG cElems;
HRESULT hr = PropVariantToInt32VectorAlloc(propvar, &prgLongs, &cElems);
if (SUCCEEDED(hr))
{
     // prgLongs now points to a vector of cElems LONGs.
     CoTaskMemFree(prgLongs);
}

Requirements

See also

InitPropVariantFromInt32Vector

PropVariantGetInt32Elem

PropVariantToInt32

PropVariantToInt32Vector

VariantToInt32Array