BUG: The UCOMIEnumVARIANT interface definitions for the Clone method and for the Next method are incorrect in the .NET Framework 1.1 and in the .NET Framework 1.0

View products that this article applies to.

This article was previously published under Q327094

Expand all | Collapse all

SYMPTOMS

The signatures for the unmanaged IEnumVARIANT::Next method and for the IEnumVARIANT::Clone method are the following.

IEnumVARIANT::Next
HRESULT Next( 
  unsigned long  celt,              
  VARIANT FAR*  rgVar,              
  unsigned long FAR*  pCeltFetched  
);


IEnumVARIANT::Clone
HRESULT Clone( 
  IEnumVARIANT FAR* FAR*  ppEnum  
);

However, the UCOMIEnumVARIANT interface does not define these methods correctly. The following are the current incorrect signatures for these methods.

UCOMIEnumVARIANT.Next
int Next(
   int celt,
   int rgvar,
   int pceltFetched
);

UCOMIEnumVARIANT.Clone
void Clone(
   int ppenum
);

Note In the UCOMIEnumVARIANT.Next method, the rgvar parameter is defined as an int instead of as an object. Additionally, in the UCOMIEnumVARIANT.Clone method, the ppenum parameter is defined as an int instead of as UCOMIEnumVARIANT. Therefore, it is difficult to use the UCOMIEnumVARIANT interface to enumerate a collection of variants.

Back to the top

WORKAROUND

You can write you own definition of the IEnumVARIANT interface. The following code is an example on how to do this.

[
ComImport(),
Guid("00020404-0000-0000-C000-000000000046"),
InterfaceType(ComInterfaceType.InterfaceIsIUnknown)
]
interface IEnumVARIANT
{
	[PreserveSig()]
	int Next(
		int celt,
		out object rgVar,
		out int pCeltFetched);

	[PreserveSig()]
	int Skip(
		int celt);

	[PreserveSig()]
	uint Reset();

	IEnumVARIANT Clone();
}

Back to the top