VB2008 Button外觀 以及一些問題

Imports System.Windows
Imports System.Drawing.Drawing2D


Public Class CustomButton


    Private pow2 As Func(Of Double, Double) =
        Function(a As Double) As Double
            Return a * a
        End Function


    Private m_mouseOn As Boolean = False
    Private m_mouseDown As Boolean = False




    Private Property _MouseOn As Boolean
        Get
            Return m_mouseOn
        End Get
        Set(ByVal value As Boolean)
            If value <> m_mouseOn Then
                m_mouseOn = value
                ' redraw
                Me.Invalidate()
                Me.Update()
                ' cursor
                If m_mouseOn Then
                    Me.Cursor = Cursors.Hand
                Else
                    Me.Cursor = Cursors.Default
                End If
            Else
                m_mouseOn = value
            End If
        End Set
    End Property


    Private Property _MouseDown As Boolean
        Get
            Return m_mouseDown
        End Get
        Set(ByVal value As Boolean)
            If value <> m_mouseDown Then
                m_mouseDown = value
                ' redraw
                Me.Invalidate()
                Me.Update()
            Else
                m_mouseDown = value
            End If
        End Set
    End Property




    Private Sub Form_Load() Handles MyBase.Load
        'Me.SetStyle(ControlStyles.AllPaintingInWmPaint Or
        '            ControlStyles.UserPaint Or
        '            ControlStyles.OptimizedDoubleBuffer Or
        '            ControlStyles.ResizeRedraw, True)
    End Sub


    Protected Overrides Sub OnResize(ByVal e As System.EventArgs)
        Me.Size = New Size(101, 101)


        MyBase.OnResize(e)
    End Sub


    Protected Overrides Sub OnPaint(ByVal e As Forms.PaintEventArgs)
        Dim rect As New Rectangle(1, 1, 98, 98)
        Dim img As New Bitmap(Me.DisplayRectangle.Width,
                              Me.DisplayRectangle.Height)
        Dim gImg As Graphics = Graphics.FromImage(img)


        ' set smoothing mode
        gImg.SmoothingMode = SmoothingMode.HighQuality


        ' fill background
        Using b As New SolidBrush(Me.BackColor)
            gImg.FillRectangle(b, rect)
        End Using


        ' is mouse down?
        If m_mouseDown Then
            If m_mouseOn Then
                Using b As New SolidBrush(Color.Green)
                    gImg.FillEllipse(b, rect)
                End Using
            End If
        Else
            ' is mouse on?
            If m_mouseOn Then
                Using b As New SolidBrush(Color.LawnGreen)
                    gImg.FillEllipse(b, rect)
                End Using
            End If
        End If


        ' draw button border
        Using p As New Pen(Brushes.Black, 2)
            gImg.DrawEllipse(p, rect)
        End Using


        ' draw text
        Using f As New Font(SystemFonts.DefaultFont.FontFamily,
                            16.0F, FontStyle.Bold)
            Dim s As String = "ABC"
            Dim fSize As Size = gImg.MeasureString(s, f).ToSize


            gImg.DrawString(s, f,
                            Brushes.Black,
                            49 - fSize.Width \ 2,
                            49 - fSize.Height \ 2)
        End Using


        ' draw image
        e.Graphics.DrawImage(img, 0, 0)


        ' dispose
        img.Dispose()
        gImg.Dispose()


        MyBase.OnPaint(e)
    End Sub


    Protected Overrides Sub OnMouseMove(ByVal e As Forms.MouseEventArgs)
        Dim vecX As Double = CDbl(e.X) - 50.0
        Dim vecY As Double = CDbl(e.Y) - 50.0


        If Math.Sqrt(pow2(vecX) + pow2(vecY)) <= 50.0 Then
            _MouseOn = True
        Else
            _MouseOn = False
        End If


        MyBase.OnMouseMove(e)
    End Sub


    Protected Overrides Sub OnMouseDown(ByVal e As Forms.MouseEventArgs)
        If m_mouseOn Then
            _MouseDown = True
        End If


        MyBase.OnMouseDown(e)
    End Sub


    Protected Overrides Sub OnMouseUp(ByVal e As Forms.MouseEventArgs)
        _MouseDown = False


        MyBase.OnMouseUp(e)
    End Sub


    Protected Overrides Sub OnMouseLeave(ByVal e As EventArgs)
        _MouseOn = False


        MyBase.OnMouseLeave(e)
    End Sub


End Class