来自C＃DLL的用户定义对象的VBA数组

Question

Background information:
I'm building a SCADA system, which runs on VBA and I seek some of the powers of C#. I build a DLL library in C# and got basic data to flow between the DLL and VBA.

[ComVisible(true), ClassInterface(ClassInterfaceType.AutoDual)]
public class BE_Log
{
    public string DateTime
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string User
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string SCADA
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string Tag
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string Area1
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string Area2
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string Description
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string ValueOld
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }
    public string ValueNew
    {
        [return: MarshalAs(UnmanagedType.BStr)]
        get;
        [param: MarshalAs(UnmanagedType.BStr)]
        set;
    }

    public BE_Log(string DataTime, string User, string SCADA, string Tag, string Area1, string Area2,string Description)
    {
        this.DateTime = DateTime;
        this.User = User;
        this.SCADA = SCADA;
        this.Tag = Tag;
        this.Area1 = Area1;
        this.Area2 = Area2;
        this.Description = Description;
    }

    public BE_Log(string DataTime, string User, string SCADA, string Tag, string Area1, string Area2, string Description, string ValueOld, string ValueNew)
    {
        this.DateTime = DateTime;
        this.User = User;
        this.SCADA = SCADA;
        this.Tag = Tag;
        this.Area1 = Area1;
        this.Area2 = Area2;
        this.Description = Description;
        this.ValueOld = ValueOld;
        this.ValueNew = ValueNew;
    }

}

And I returned the class like this:

[ComVisible(true), ClassInterface(ClassInterfaceType.AutoDual)]
public class TI
{
    private BLL_LogBook bll;

    public TI()
    {
        bll = new BLL_LogBook();
    }

    [return: MarshalAs(UnmanagedType.SafeArray, SafeArraySubType=VarEnum.VT_USERDEFINED)]  //  SafeArrayUserDefinedSubType = typeof(BE_Log)
    public BE_Log[] CreateLogBook()
    {
        List<BE_Log> logs = bll.GetLogEntry();
        return logs.ToArray();
    }
}

My data layer:

public class BLL_LogBook
{
    public List<BE_Log> GetLogEntry()
    {
        List<BE_Log> logs = new List<BE_Log>();
        logs.Add(new BE_Log("05-05-2015", "some user", "scada01", "LA010NDA10CU12XQ12", "Ribe", "Esbjerg", "Some short description"));
        logs.Add(new BE_Log("06-05-2015", "test user", "scada01", "LA010NDA10CU12XB05", "Herning", "KBH", "Some long description"));
        logs.Add(new BE_Log("07-05-2015", "normal user", "scada02", "LA010NDA10CU12YQ01", "Åhus", "Tønder", "Some test description"));

        return logs;
    }
}

The static method VBA is calling:

static class UnmanagedExports
{
    [DllExport]
    [return: MarshalAs(UnmanagedType.IDispatch)]
    static Object TI_Object()
    {
        return new TI();
    }
}

In VBA i got the data this way:

Declare Function TI_Object Lib "<path>\\TJI.dll" () As Object

Sub TestTheTestClass()
    Dim TJI As Object
    Set TJI = TI_Object()

    Dim test As Variant
    test = TJI.CreateLogBook()

    Dim log As Variant
    Set log = test(0)

    Debug.Print log.User
End Sub

Now to my question:
How do I return an Array or List of the class 'BE_Log'
EDIT: This is where I'm stuck: http://puu.sh/hnPGe/472ff863d0.png

I have been trying to work out some of Microsofts documentations, without much luck.

The orginal guide i followed was this one:
http://www.analystcave.com/excel-use-c-sharp-in-excel-vba/

He states the following, however I dont completely understand it.

If you are using an array as an argument be sure to use the C# “ref” get by reference option eg ref int[] ar

I think it's something to do with 'MarshalAs' or the way I read the data in VBA

Answer 1

If you are using an array as an argument be sure to use the C# “ref” get by reference option eg ref int[] ar

This is true, but you don't have any methods that take an array argument, so it doesn't apply to your situation.

Have you tried changing your method signature:

public Log CreateLogBook()

to a signature that returns an array:

public Log[] CreateLogBook()