Public Class ComboBoxEx
    Inherits System.Windows.Forms.ComboBox
    Private mclrDropDownStyle As ComboBoxStyle
    Private mclrAutoCompleteMode As AutoCompleteMode
    Private mclrAutoCompleteSource As AutoCompleteSource


#Region "Declarations"

    Private InEditMode As Boolean = True

#End Region

#Region "Constructor"

    Public Sub ComboBoxEx()

        Me.DropDownStyle = ComboBoxStyle.DropDown
        Me.AutoCompleteMode = AutoCompleteMode.SuggestAppend
        Me.AutoCompleteSource = AutoCompleteSource.ListItems
    End Sub


#End Region

#Region "Properties"

    Public Overloads Property DropDownStyle() As ComboBoxStyle

        Get
            Return DropDownStyle
        End Get
        Set(ByVal Value As ComboBoxStyle)
            mclrDropDownStyle = Value
        End Set
    End Property

    'DefaultValue(typeof(AutoCompleteMode), "SuggestAppend")
    Public Overloads Property AutoCompleteMode() As AutoCompleteMode

        Get
            Return AutoCompleteMode
        End Get
        Set(ByVal Value As AutoCompleteMode)
            mclrAutoCompleteMode = Value
        End Set

    End Property

    '[DefaultValue(typeof(AutoCompleteSource), "ListItems")]
    Public Overloads Property AutoCompleteSource() As AutoCompleteSource

        Get
            Return AutoCompleteSource
        End Get

        Set(ByVal value As AutoCompleteSource)

            mclrAutoCompleteSource = value
        End Set

    End Property

#End Region

#Region "Events"

    Protected Overrides Sub OnBindingContextChanged(ByVal e As EventArgs)

        Me.DropDownStyle = ComboBoxStyle.DropDown
        MyBase.OnBindingContextChanged(e)
    End Sub

    Protected Shadows Sub OnValidating(ByVal e As System.ComponentModel.CancelEventArgs)


        Dim index = FindStringExact(Text)

        If (index >= 0) Then
            MyBase.OnValidating(e)
        Else
            If (Text.Trim() = "") Then

                ' do nothing

            Else

                e.Cancel = True
            End If
        End If

    End Sub


    Protected Overrides Sub OnKeyDown(ByVal e As KeyEventArgs)

        Me.InEditMode = (e.KeyCode <> Keys.Back And e.KeyCode <> Keys.Delete)
        MyBase.OnKeyDown(e)
    End Sub
    Protected Overrides Sub OnTextChanged(ByVal e As EventArgs)

        If (Me.InEditMode) Then

            Dim index = Me.FindString(Me.Text)

            If (index < 0 And Text.Trim() <> "") Then

                InEditMode = False
                Me.Text = Text.Substring(0, Text.Length - 1)
                Me.InEditMode = True
            End If
        End If

        Select Case (Me.Text.Length)

        End Select
        MyBase.OnTextChanged(e)
    End Sub

#End Region

End Class