Visual Basic

Imports System.Drawing
Imports System.Windows.Forms
Imports System.ComponentModel

<DesignerCategory("Component"), _
DefaultProperty("DataSource"), _
TypeConverter("System.Windows.Forms.Design.DataSourceConverter"), _
ToolboxItem(True)> _
Public Class DataComboBoxEx : Inherits ComboBoxEx
'Or - Public Class DataListBoxEx : Inherits ListBoxEx

    Private _Columns As DataColumnCollection
    Private _GridLineColor As Color
    Private _ShowHorizontalGridLines As Boolean
    Private _ShowVerticalGridLines As Boolean

    Public Sub New()
        _ShowVerticalGridLines = True
        _ShowHorizontalGridLines = False
        _Columns = New DataColumnCollection()
        _Columns.Parent = Me

        _GridLineColor = SystemColors.ControlDark
        ItemHeight = Math.Max(ItemHeight, 22)
    End Sub

    Protected Overrides Sub DrawItemText( _
            ByVal e As System.Windows.Forms.DrawItemEventArgs)

        Dim rItem As Rectangle = e.Bounds
        Dim g As Graphics = e.Graphics
        Dim gPen As New Pen(_GridLineColor)
        Dim DS As Object
        If DataSource Is Nothing Then
            DS = Items
        Else
            DS = DataSource
        End If

        Dim rItemF As New RectangleF(rItem.X, rItem.Y, rItem.Width, rItem.Height)
        Dim oItem As DataColumn
        For Each oItem In _Columns
            rItemF.Width = oItem.Width
            oItem.OnDraw(e, rItemF, DS, DisplayMember)
            If _ShowVerticalGridLines Then
                g.DrawLine(gPen, rItemF.Right, rItemF.Y, rItemF.Right, rItemF.Bottom)
            End If
            rItemF.X += rItemF.Width
        Next
        If _ShowHorizontalGridLines Then
            g.DrawLine(gPen, rItem.X, rItem.Bottom - 1, rItem.Right, rItem.Bottom - 1)
        End If

        gPen.Dispose()
    End Sub

    <Category("Behavior"), _
    DesignerSerializationVisibility(DesignerSerializationVisibility.Content)> _
    Public Property Columns() As DataColumnCollection
        Get
            Return _Columns
        End Get
        Set(ByVal Value As DataColumnCollection)
            _Columns = Value
            _Columns.Parent = Me
        End Set
    End Property

    <Category("Appearance")> _
    Public Property GridLineColor() As Color
        Get
            Return _GridLineColor
        End Get
        Set(ByVal Value As Color)
            _GridLineColor = Value
        End Set
    End Property

    <Category("Appearance"), DefaultValue(False)> _
    Public Property ShowHorizontalGridLines() As Boolean
        Get
            Return _ShowHorizontalGridLines
        End Get
        Set(ByVal Value As Boolean)
            _ShowHorizontalGridLines = Value
        End Set
    End Property

    <Category("Appearance"), DefaultValue(True)> _
    Public Property ShowVerticalGridLines() As Boolean
        Get
            Return _ShowVerticalGridLines
        End Get
        Set(ByVal Value As Boolean)
            _ShowVerticalGridLines = Value
        End Set
    End Property

#Region "Hide properies"
    <Browsable(False)> _
    Public Shadows Property DropDownStyle() As ComboBoxStyle
        Get
            Return ComboBoxStyle.DropDown
        End Get
        Set(ByVal Value As ComboBoxStyle)
            MyBase.DropDownStyle = ComboBoxStyle.DropDown
        End Set
    End Property

    <Browsable(False)> _
    Public Shadows Property Sorted() As Boolean
        Get
            Return MyBase.Sorted
        End Get
        Set(ByVal Value As Boolean)
            MyBase.Sorted = Value
        End Set
    End Property
#End Region

End Class

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (lpvDest As Any, lpvSource As Any, ByVal cbCopy As Long)

Public Function Long2Sng(ByVal InVal As Long) As Single
Dim sRet As Single
    CopyMemory sRet, InVal, 4
    Long2Sng = sRet
End Function