Imports System.Data.OleDb
Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "
#End Region

    Public MyCombo As New ComboBox()

    Dim sDBNAme As String = "c:\TestDB\Northwind.mdb"
    Dim sConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & sDBNAme & ";Persist Security Info=False"
    Dim con As New OleDbConnection(sConn)
    Dim daEmp As New OleDbDataAdapter("Select * From Employees", con)

    Public ds As New DataSet()


    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AddHandler MyCombo.TextChanged, AddressOf Ctrls_TextChanged
        'Fill ComboBox list.
        MyCombo.Name = "MyCombo"
        MyCombo.Visible = False
        MyCombo.Items.Clear()
        MyCombo.Items.Add("Sales Representative")
        MyCombo.Items.Add("Inside Sales Coordinator")
        MyCombo.Items.Add("Vice President, Sales")
        MyCombo.Items.Add("Sales Manager")
        MyCombo.Items.Add("Flunky")

        daEmp.Fill(ds, "Employees")

        'Set the RowHeight of the DataGrid to the height of the ComboBox.
        DataGrid1.PreferredRowHeight = MyCombo.Height

        DataGrid1.DataSource = ds

        DataGrid1.DataMember = "Employees"
        'Add ComboBox to the Control collection of the DataGrid.
        DataGrid1.Controls.Add(MyCombo)
    End Sub
    Private Sub DataGrid1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles DataGrid1.Paint
        If DataGrid1.CurrentCell.ColumnNumber = 3 Then
            MyCombo.Width = DataGrid1.GetCurrentCellBounds.Width
        End If
    End Sub

    Private Sub Ctrls_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs)
        If DataGrid1.CurrentCell.ColumnNumber = 3 Then
            MyCombo.Visible = False
            If DataGrid1.Item(DataGrid1.CurrentCell) & "" = "" Then
                SendKeys.Send("*")
            End If
            DataGrid1.Item(DataGrid1.CurrentCell) = MyCombo.Text
        End If
    End Sub

    Private Sub DataGrid1_CurrentCellChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DataGrid1.CurrentCellChanged
        If DataGrid1.CurrentCell.ColumnNumber = 3 Then
            MyCombo.Visible = False
            MyCombo.Width = 0
            MyCombo.Left = DataGrid1.GetCurrentCellBounds.Left
            MyCombo.Top = DataGrid1.GetCurrentCellBounds.Top
            MyCombo.Text = DataGrid1.Item(DataGrid1.CurrentCell) & ""
            MyCombo.Visible = True
        Else
            MyCombo.Visible = False
            MyCombo.Width = 0
        End If
    End Sub

    Private Sub DataGrid1_Scroll(ByVal sender As Object, ByVal e As System.EventArgs) Handles DataGrid1.Scroll
        MyCombo.Visible = False
        MyCombo.Width = 0
    End Sub

    Private Sub DataGrid1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles DataGrid1.Click
        MyCombo.Visible = False
        MyCombo.Width = 0
    End Sub

End Class