Public Class FlatCombo
    Inherits ComboBox
 
    Private BorderPen = New Pen(SystemColors.ControlDarkDark, 1)
    Private BorderBrush As Brush = New SolidBrush(SystemColors.Window)
    Private ArrowBrush As Brush = New SolidBrush(SystemColors.ControlText)
    Private DropButtonBrush As Brush = New SolidBrush(SystemColors.Control)
    Private _ButtonColor As Color = SystemColors.Control
 
    Public Property ButtonColor() As Color
        Get
            Return _ButtonColor
        End Get
        Set(ByVal Value As Color)
            _ButtonColor = Value
            DropButtonBrush = New SolidBrush(Me.ButtonColor)
            Me.Invalidate()
        End Set
    End Property
 
    Dim borderWidth As Integer = 1
 
    Protected Overrides Sub WndProc(ByRef m As Message)
        MyBase.WndProc(m)
 
        Select Case m.Msg
            Case &HF
                'Paint the background. Only the borders
                'will show up because the edit
                'box will be overlayed
                Dim g As Graphics = Me.CreateGraphics
                'Dim p As Pen = New Pen(Color.White, 2)
                g.FillRectangle(BorderBrush, Me.ClientRectangle)
 
                ' Draw the border
                Debug.WriteLine(Me.ClientRectangle.ToString())
                g.DrawRectangle(BorderPen, 0, 0, Me.ClientRectangle.Width - 1, _
                  Me.ClientRectangle.Height - 1)
 
                'Draw the background of the dropdown button
                Dim rect As Rectangle = New Rectangle(Me.Width - 15, 1, 14, _
                  Me.Height - 2)
                g.FillRectangle(DropButtonBrush, rect)
 
                'Create the path for the arrow
                Dim pth As Drawing2D.GraphicsPath = New Drawing2D.GraphicsPath
                Dim TopLeft As PointF = New PointF(Me.Width - 13, (Me.Height - _
                  5) / 2)
                Dim TopRight As PointF = New PointF(Me.Width - 6, (Me.Height - _
                5) / 2)
                Dim Bottom As PointF = New PointF(Me.Width - 9, (Me.Height + 2) _
                / 2)
                pth.AddLine(TopLeft, TopRight)
                pth.AddLine(TopRight, Bottom)
 
                g.SmoothingMode = Drawing2D.SmoothingMode.HighQuality
 
                'Determine the arrow's color.
                If Me.DroppedDown Then
                    ArrowBrush = New SolidBrush(SystemColors.HighlightText)
                Else
                    ArrowBrush = New SolidBrush(SystemColors.ControlText)
                End If
 
                'Draw the arrow
                g.FillPath(ArrowBrush, pth)
 
            Case Else
                Exit Select
        End Select
    End Sub
 
    'Override mouse and focus events to draw
    'proper borders. Basically, set the color and Invalidate(),
    'In general, Invalidate causes a control to redraw itself.
#Region "Mouse and focus Overrides"
    Protected Overrides Sub OnMouseEnter(ByVal e As System.EventArgs)
        MyBase.OnMouseEnter(e)
        Me.Invalidate()
    End Sub
 
    Protected Overrides Sub OnMouseLeave(ByVal e As System.EventArgs)
        MyBase.OnMouseLeave(e)
        If Me.Focused Then Exit Sub
        Me.Invalidate()
    End Sub
 
    Protected Overrides Sub OnLostFocus(ByVal e As System.EventArgs)
        MyBase.OnLostFocus(e)
        Me.Invalidate()
    End Sub
 
    Protected Overrides Sub OnSelectedIndexChanged(ByVal e As System.EventArgs)
        MyBase.OnSelectedIndexChanged(e)
        Me.Invalidate()
    End Sub
 
#End Region
 
End Class

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