PropVariantToCLSID function

Extracts class identifier (CLSID) property value of a PROPVARIANT structure.

Syntax

HRESULT PropVariantToCLSID(
  _In_  REFPROPVARIANT propvar,
  _Out_ CLSID          *pclsid
);

Parameters

propvar [in]

Type: REFPROPVARIANT

Reference to a source PROPVARIANT structure.

pclsid [out]

Type: CLSID*

When this function returns, contains the extracted property value if one exists.

Return value

Type: HRESULT

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

Remarks

This helper function works forPROPVARIANTstructures of the following types:

• VT_CLSID
• VT_BSTR
• VT_LPWSTR
• VT_ARRAY | VT_UI1

This is an inline function, with its source code provided in the header. It is not included in any .dll or .lib file.

PropVariantToCLSID is used in places where the calling application expects a PROPVARIANT to hold a single CLSID or GUID value. For instance, an application obtaining values from a property store can use this to safely extract the CLSID value for GUID properties.

Examples

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

// IPropertyStore *ppropstore;
// Assume variable ppropstore is initialized and valid
PROPVARIANT propvar = {0};

HRESULT hr = ppropstore->GetValue(PKEY_Sync_HandlerCollectionID, &propvar);
if (SUCCEEDED(hr))
{
        // PKEY_Sync_HandlerCollectionID is expected to produce a VT_CLSID or VT_EMPTY value.
        // PropVariantToCLSID will convert VT_EMPTY to a failure code.
        CLSID clsidCollectionID;

        hr = PropVariantToCLSID(propvar, &clsidCollectionID);
        if (SUCCEEDED(hr))
        {
             // clsidCollectionID is now valid
        }
        else
        {
            // the extraction failed
        }
        PropVariantClear(&propvar);
}

Requirements

See also

InitPropVariantFromCLSID

PropVariantToGUID

VariantToGUID