EN
Dieser Inhalt ist in Ihrer Sprache leider nicht verfügbar. Im Folgenden finden Sie die englische Version.

PropVariantToUInt32VectorAlloc function

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

Syntax


HRESULT PropVariantToUInt32VectorAlloc(
  _In_   REFPROPVARIANT propvar,
  _Out_  ULONG **pprgn,
  _Out_  ULONG *pcElem
);

Parameters

propvar [in]

Type: REFPROPVARIANT

Reference to a source PROPVARIANT structure.

pprgn [out]

Type: ULONG**

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

pcElem [out]

Type: ULONG*

When this function returns, contains the count of ULONG values 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 ULONG values.

If the source PROPVARIANT has type VT_VECTOR | VT_UI4 or VT_ARRAY | VT_UI4, this function extracts a vector of ULONG 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 PropVariantToUInt32VectorAlloc to access a ULONG 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 ULONG values.
ULONG *prgLongs;
ULONG cElems;
HRESULT hr = PropVariantToUInt32VectorAlloc(propvar, &prgLongs, &cElems);
if (SUCCEEDED(hr))
{
     // prgLongs now points to a vector of cElems ULONG.
     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

InitPropVariantFromUInt32Vector
PropVariantToUInt32
PropVariantGetUInt32Elem
PropVariantToUInt32Vector
VariantToUInt32Array

 

 

Community-Beiträge

HINZUFÜGEN
Anzeigen:
© 2014 Microsoft