PropVariantGetUInt64Elem function (propvarutil.h)

Article
02/22/2024

Extracts a single unsigned Int64 element from a PROPVARIANT structure of type VT_UI8, VT_VECTOR | VT_UI8, or VT_ARRAY | VT_UI8.

Syntax

PSSTDAPI PropVariantGetUInt64Elem(
  [in]  REFPROPVARIANT propvar,
  [in]  ULONG          iElem,
  [out] ULONGLONG      *pnVal
);

Parameters

[in] propvar

Type: REFPROPVARIANT

The source PROPVARIANT structure.

[in] iElem

Type: ULONG

The vector or array index; otherwise, iElem must be 0.

[out] pnVal

Type: ULONGLONG*

When this function returns, contains the extracted Int64 value.

Return value

Type: HRESULT

If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

This helper function works for PROPVARIANT structures of the following types:

VT_UI8
VT_VECTOR | VT_UI8
VT_ARRAY | VT_UI8

If the source PROPVARIANT has type VT_UI8, iElem must be 0. Otherwise iElem must be less than the number of elements in the vector or array. You can use PropVariantGetElementCount to obtain the number of elements in the vector or array.

Examples

The following example, to be included as part of a larger program, demonstrates how to use PropVariantGetUInt64Elem with an iteration statement to access the values in a PROPVARIANT.

// PROPVARIANT propvar;
// Assume the variable propvar is initialized and valid

if ((propvar.vt & VT_TYPEMASK) == VT_UI8)
{
    UINT cElem = PropVariantGetElementCount(propvar);
    HRESULT hr = <mark type="const">S_OK</mark>;

    for (UINT iElem = 0; SUCCEEDED(hr) && iElem < cElem; iElem ++)
    {
        ULONGLONG nValue;
        hr = PropVariantGetUInt64Elem(propvar, iElem, &nValue);

        if (SUCCEEDED(hr))
        {
            // nValue is valid now
        }
    }
}

Requirements

Requirement	Value
Minimum supported client	Windows XP with SP2, Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2003 with SP1 [desktop apps only]
Target Platform	Windows
Header	propvarutil.h
Library	Propsys.lib
DLL	Propsys.dll (version 6.0 or later)
Redistributable	Windows Desktop Search (WDS) 3.0

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