Dim bzpoints() As Point = {New Point(50, 400), New Point(250, 400), New _
      Point(400, 400), New Point(450, 100)}
    Dim CheckPoint As New ArrayList
 
    Dim gpath As New GraphicsPath
    Dim curpoint As Int32
    Dim ptsvisible As Boolean
    Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown
        curpoint = -1
        If ptsvisible AndAlso gpath.IsVisible(New Point(e.X, e.Y)) Then
            For i As Int32 = 1 To 2
                If Math.Abs(e.X - bzpoints(i).X) < 6 AndAlso Math.Abs(e.Y - _
                  bzpoints(i).Y) < 6 Then
                    curpoint = i
                End If
            Next
        End If
        If e.Button = Windows.Forms.MouseButtons.Right Then
            ptsvisible = Not ptsvisible
            Me.Refresh()
        End If
    End Sub
    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        e.Graphics.SmoothingMode = SmoothingMode.HighQuality
        For Each h As Point In CheckPoint
            e.Graphics.DrawPie(Pens.Green, h.X - 5, h.Y - 5, 10, 10, 0, 360)
 
        Next
        e.Graphics.DrawBezier(New Pen(Color.Yellow, 2), bzpoints(0), bzpoints( _
          1), bzpoints(2), bzpoints(3))
        If ptsvisible Then
            gpath.Reset()
            For i As Int32 = 0 To 3
                gpath.AddEllipse(bzpoints(i).X - 5, bzpoints(i).Y - 5, 10, 10)
            Next
            e.Graphics.FillPath(Brushes.Red, gpath)
        End If
 
 
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        CheckPoint.Add(New Point(0, 0))
 
        Me.SetStyle(ControlStyles.DoubleBuffer Or ControlStyles.UserPaint Or _
          ControlStyles.AllPaintingInWmPaint, True)
        Me.SetBounds(100, 100, 500, 500)
        Me.BackColor = Color.Black
    End Sub
    Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove
        If ptsvisible AndAlso curpoint > -1 AndAlso e.Button = _
        Windows.Forms.MouseButtons.Left Then
            bzpoints(curpoint) = New Point(e.X, e.Y)
            Me.Refresh()
        End If
    End Sub
 
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        bzpoints(0) = New Point(100, 400)
        bzpoints(1) = New Point(200, 300)
        bzpoints(2) = New Point(300, 200)
        bzpoints(3) = New Point(400, 100)
        Refresh()
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        Dim ay, ax, by, bx, cy, cx, pty, ptx, t As Double
        CheckPoint.Clear()
        For t = 0 To 1 Step 0.2
            CheckPoint.Add(BezierPos(t))
        Next
        Refresh()
    End Sub
    Function BezierPos(ByVal t As Double) As Point
        Dim p As Point
        p.X = bzpoints(0).X * t ^ 3 + bzpoints(1).X * 3 * t ^ 2 * (1 - t) + _
          bzpoints(2).X * 3 * t * (1 - t) ^ 2 + bzpoints(3).X * (1 - t) ^ 3
        p.Y = bzpoints(0).Y * t ^ 3 + bzpoints(1).Y * 3 * t ^ 2 * (1 - t) + _
        bzpoints(2).Y * 3 * t * (1 - t) ^ 2 + bzpoints(3).Y * (1 - t) ^ 3
        Return p
    End Function