Visual Basic

Option Explicit

Private Sub btnTest_Click()
    Dim strTest(4) As String
    strTest(1) = "abc"
    strTest(2) = "def"
    strTest(3) = "ghi"
    strTest(4) = "jkl"
    
    On Error GoTo err1
        
    Dim clsTest As ComTest.clsValues
    Set clsTest = New ComTest.clsValues
    
    clsTest.SingleString = "this is my string"
    clsTest.stringArray = strTest   ' <<<ERROR IS HERE
    
    MsgBox "Single string = " & clsTest.SingleString, vbInformation, "Test"
    
    Dim x As Integer
    
    For x = 0 To UBound(clsTest.StringArray)
        MsgBox "Multi string 2 = " & clsTest.StringArray(x), vbInformation, "Test"
    Next x
    
    Exit Sub
    
: err1
    MsgBox "Error: " & Err.Number & vbCrLf & Err.Description, vbCritical, "btnTest_Click"
    On Error Resume Next
    
End Sub

Imports System.Runtime.InteropServices

<ComClass(clsValues.ClassId, clsValues.InterfaceId, clsValues.EventsId)> _
Public Class clsValues

#Region "COM GUIDs"
    ' These  GUIDs provide the COM identity for this class 
    ' and its COM interfaces. If you change them, existing 
    ' clients will no longer be able to access the class.
    Public Const ClassId As String = "095dc64d-141f-46f9-9af2-1c5e633b459b"
    Public Const InterfaceId As String = "86ec1f14-1ef4-446d-9172-b92cf260cd16"
    Public Const EventsId As String = "1605e412-8b11-4ee0-a34c-9ec04464737f"
#End Region

    ' A creatable COM class must have a Public Sub New() 
    ' with no parameters, otherwise, the class will not be 
    ' registered in the COM registry and cannot be created 
    ' via CreateObject.
    Public Sub New()
        MyBase.New()
    End Sub

    Private mSingleString As String
    Public Property SingleString() As String
        Get
            Return mSingleString
        End Get
        Set(ByVal value As String)
            mSingleString = value
        End Set
    End Property

    Private mStringArray() As String
    Public Property StringArray() As <MarshalAs(UnmanagedType.SafeArray, safearraysubtype:=VarEnum.VT_BSTR)> String()
        Get
            Return mStringArray
        End Get
        Set(<MarshalAs(UnmanagedType.SafeArray, safearraysubtype:=VarEnum.VT_BSTR)> ByVal value As String())
            mStringArray = value
        End Set
    End Property

End Class

Imports System

Public NotInheritable Class SplashScreen1

    Private Sub SplashScreen1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        'Set up the dialog text at runtime according to the application's assembly information.  

        'TODO: Customize the application's assembly information in the "Application" pane of the project 
        '  properties dialog (under the "Project" menu).

        'Application title
        If My.Application.Info.Title <> "" Then
            SplashScreenForm.Text = My.Application.Info.Title
        Else
            'If the application title is missing, use the application name, without the extension
            SplashScreenForm.Text = System.IO.Path.GetFileNameWithoutExtension(My.Application.Info.AssemblyName)
        End If

        'Format the version information using the text set into the Version control at design time as the
        '  formatting string.  This allows for effective localization if desired.
        '  Build and revision information could be included by using the following code and changing the 
        '  Version control's designtime text to "Version {0}.{1:00}.{2}.{3}" or something similar.  See
        '  String.Format() in Help for more information.
        '
        '    Version.Text = System.String.Format(Version.Text, My.Application.Info.Version.Major, My.Application.Info.Version.Minor, My.Application.Info.Version.Build, My.Application.Info.Version.Revision)

        Version.Text = System.String.Format(Version.Text, My.Application.Info.Version.Major, My.Application.Info.Version.Minor)

        'Copyright info
        Copyright.Text = My.Application.Info.Copyright
        Copyright.Show()

        'Show the Splash Screen
        Me.Show()
        Me.Focus()

        'Pause for 5 seconds
        Threading.Thread.Sleep(5000)

        'Hide the Splash Screen and show the First Form
        Me.WindowState = FormWindowState.Minimized
        Me.Visible = False
        MenuEditorForm.Show()
        MenuEditorForm.TopMost = True
    End Sub

End Class