C# Definition:

[ComImport]
[Guid("0000000d-0000-0000-C000-000000000046")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IEnumSTATSTG
{
    // The user needs to allocate an STATSTG array whose size is celt.
    [PreserveSig]
    uint
    Next(
    uint celt,
    [MarshalAs(UnmanagedType.LPArray), Out]
    STATSTG[] rgelt,
    out uint pceltFetched
    );

    void Skip(uint celt);

    void Reset();

    [return:MarshalAs(UnmanagedType.Interface)]
    IEnumSTATSTG Clone();
}

Sample Code

IEnumSTATSTG enumerator = ... ;

STATSTG s = new STATSTG[1];
uint r;

while( e.Next(1, s, out r) == 0 )
{
     // Maniputlate s[0];
}

Notes:

This is a good example on how to marshal IEnumXXX interfaces.