C# Definition:

    [ComImport]
    [Guid("E357FCCD-A995-4576-B01F-234630154E96")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    interface IThumbnailProvider {
        void GetThumbnail(
            int cx,
            out IntPtr phbmp,
            out WTS_ALPHATYPE pdwAlpha
            );
    }

User-Defined Types (C#):

    enum WTS_ALPHATYPE {
        WTSAT_UNKNOWN = 0,
        WTSAT_RGB = 1,
        WTSAT_ARGB = 2,
    }

VB Definition:

    <ComImport> _
    <Guid("E357FCCD-A995-4576-B01F-234630154E96")> _
    <InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
    Interface IThumbnailProvider
        Sub GetThumbnail(cx As Integer, ByRef phbmp As IntPtr, ByRef pdwAlpha As WTS_ALPHATYPE)
    End Interface

User-Defined Types (VB):

    Enum WTS_ALPHATYPE
        WTSAT_UNKNOWN = 0
        WTSAT_RGB = 1
        WTSAT_ARGB = 2
    End Enum

Notes:

None.