Using your C# Components in Visual Basic through COM

Hello Mike,
We have a VB application that hosts VB.Net (framework 2.0) user controls via VC++ 6.0 type libraries. In the VB.Net user control we have a data grid view with text box, combo box and check box.
When hosted to VB form via VC++ type libraries, we are not able to edit the text box.
(there are other problems too, like combo drop down appears in some ohter place of the form, check box gets checked only sometimes etc.)
The same dot net user control works fine when hosted onto VB directly, without using these VC++ type libraries.

The following is the interface of the type library
[
  uuid (9EF896B1-AB19-11d3-9A8E-0050DA3393D8),
  version (1.0),
  dual,
  nonextensible,
  oleautomation
]
interface ICustomControl : IDispatch {
    // Property: CallBack
    [ helpstring("Set/get a reference to the control's CallBack object, through which it will send events.")]
    [propget]    HRESULT CallBack([out, retval] ICallBack** );
    [propputref] HRESULT CallBack([in] ICallBack* icbPipe);

    // Property: hWnd
    [ helpstring("Returns the control's window handle.")]
    [propget]   HRESULT hWnd([out, retval] long* );

    // Property: Visible
    [helpstring("Show/hide control.")]
    [propget]   HRESULT Visible([out, retval] VARIANT_BOOL* );
    [propput]   HRESULT Visible([in] VARIANT_BOOL );

    // Property: Locked
    [ helpstring("Enable/disable data editing. Setting locked will set the control in a  \"read-only\" mode.")]
    [propget]   HRESULT Locked([out, retval] VARIANT_BOOL* );
    [propput]   HRESULT Locked([in] VARIANT_BOOL fLock);

   
    // Function: Initialize
    [ helpstring("Initialize user control with data to be shown.") ]
    HRESULT Initialize([in] VARIANT vInData);
   
    // Function: Refresh
    [ helpstring("Force repaint of control.")]  
    HRESULT Refresh();

    // Function: SetFocus
    [ helpstring("Set focus in control.")]
    HRESULT SetFocus();
}

The above interface is implemented in dot net user control (because VB is expecting this)

The following is the user control code.

Imports System.Runtime.InteropServices
Imports ABCTypeLib
Imports System.Windows.Forms
Imports System.Drawing
Imports Microsoft.VisualBasic.Compatibility

Public Class ucCustomSetup
    Inherits System.Windows.Forms.UserControl
    Implements AnsurTypeLib.ICustomControl
    <DllImport("user32.dll")> _
    Private Shared Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
    End Function
    Dim intAdded As Integer
    Private _objCallBack As ICallBack
    Private _objConfigData As IConfigData
    Private mfInitializing As Boolean
    Private _testId As Long
    Private _character As String
    Private cmbWorkflow As ComboBox
    Private dtbShortlist As DataTable
    Public WithEvents cmbFunctionArea As System.Windows.Forms.ComboBox

  ''-------------------------------------------------------------------------------
    ' Function : SendChangeEvent
    ' Synopsis:  Sends a change event to ansur.
    '-------------------------------------------------------------------------------
    Private Sub SendChangeEvent()
        On Error Resume Next
        If Not (mfInitializing Or (_objCallBack Is Nothing)) Then
            _objCallBack.SendEvent(AnsurTypeLib.CallBackConstants.CALLBACK_CHANGE)
        End If
    End Sub

    Public Property CallBack() As AnsurTypeLib.ICallBack Implements AnsurTypeLib.ICustomControl.CallBack
        Get
            CallBack = _objCallBack
        End Get
        Set(ByVal value As AnsurTypeLib.ICallBack)
            _objCallBack = value
        End Set
    End Property

    Public ReadOnly Property hWnd() As Integer Implements AnsurTypeLib.ICustomControl.hWnd
        Get
            'hWnd = MyBase.Handle.ToInt32()
            hWnd = MyBase.Handle.ToString()

        End Get
    End Property

    Public Sub Initialize(ByVal vInData As Object) Implements AnsurTypeLib.ICustomControl.Initialize
        mfInitializing = True
        PopulateGrid()
    End Sub

    Public Property Locked() As Boolean Implements AnsurTypeLib.ICustomControl.Locked
        Get
            Return False
        End Get
        Set(ByVal value As Boolean)
            DataGridView1.ReadOnly = value
        End Set
    End Property

    Public Sub Refresh1() Implements AnsurTypeLib.ICustomControl.Refresh
        MyBase.Refresh()
    End Sub

    Public Sub SetFocus() Implements AnsurTypeLib.ICustomControl.SetFocus
        DataGridView1.Focus()
    End Sub

    Public Property Visible1() As Boolean Implements AnsurTypeLib.ICustomControl.Visible
        Get
            Visible1 = MyBase.Visible
        End Get
        Set(ByVal value As Boolean)
            MyBase.Visible = value
        End Set
    End Property

    Private Sub ucCustomSetup_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
        Dim X, dx As Single
        Dim Y, dy As Single
        'Resize unit page.
        AxXHelpText1.SetBounds(VB6.TwipsToPixelsX(X), VB6.TwipsToPixelsY(Y + dy), VB6.TwipsToPixelsX(dx), VB6.TwipsToPixelsY(0))
    End Sub

    Private Sub DataGridView1_CellClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellClick
        SendChangeEvent()
    End Sub

    Private Sub DataGrid1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles DataGrid1.KeyPress, DataGridView1.KeyPress
        SendChangeEvent()

    End Sub

    Private Sub DataGrid1_Navigate(ByVal sender As System.Object, ByVal ne As System.Windows.Forms.NavigateEventArgs) Handles DataGrid1.Navigate

    End Sub

    Private Sub DataGridView1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles DataGridView1.MouseClick
        SendChangeEvent()
    End Sub
End Class

Please help us.

- Vidya