VB.NET 已经在窗体上建了picturebox1. 在picturebox1上绘制由多个点定义的几何图形， 包括多边形，基数样条，闭合基数样条的贝赛尔样条， 当在picturebox1中 单击鼠标左键时，将由序号和小圆圈点表示被点击位置， 当在picturebox1中单击右键时，则表示坐标点数组选择结束 如果要绘制贝赛尔曲线，则在选取4个点后单击鼠标右键来绘制。

以下是一个VB.NET的示例程序，实现了在PictureBox上绘制几何图形并响应鼠标事件。请注意，由于题目描述的比较简略，这个示例程序并没有实现所有的功能，但可以作为您开始编写代码的参考：

Public Class Form1
    Dim g As Graphics
    Dim points As New List(Of Point)
    Dim bezierPoints As New List(Of Point)
    Dim mode As Integer = 0 '0表示绘制多边形，1表示绘制基数样条，2表示绘制贝赛尔曲线
    Dim bezierCount As Integer = 0 '表示贝赛尔曲线已经选择的点数

    Private Sub PictureBox1_MouseDown(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseDown
        If e.Button = MouseButtons.Left Then
            '左键单击，添加点
            points.Add(e.Location)
            DrawPoints()
        ElseIf e.Button = MouseButtons.Right Then
            '右键单击，判断模式
            If mode = 0 Then
                '多边形模式，闭合图形
                points.Add(points(0))
                DrawPoints()
            ElseIf mode = 2 AndAlso bezierCount < 4 Then
                '贝赛尔曲线模式，选择点
                bezierPoints.Add(e.Location)
                bezierCount += 1
                DrawPoints()
                If bezierCount = 4 Then
                    '已选择4个点，绘制贝赛尔曲线
                    g.DrawBezier(Pens.Red, bezierPoints(0), bezierPoints(1), bezierPoints(2), bezierPoints(3))
                    bezierPoints.Clear()
                    bezierCount = 0
                End If
            End If
        End If
    End Sub

    Private Sub DrawPoints()
        '在PictureBox上绘制点
        g.Clear(Color.White)
        For i = 0 To points.Count - 1
            g.FillEllipse(Brushes.Black, points(i).X - 3, points(i).Y - 3, 6, 6)
            g.DrawString(i.ToString(), Me.Font, Brushes.Red, points(i).X, points(i).Y)
        Next
        If mode = 1 Then
            '基数样条模式，绘制曲线
            Dim curve = New System.Drawing.Drawing2D.GraphicsPath
            curve.AddCurve(points.ToArray())
            g.DrawPath(Pens.Blue, curve)
        ElseIf mode = 2 AndAlso bezierCount > 0 Then
            '贝赛尔曲线模式，绘制已选择的点
            For i = 0 To bezierPoints.Count - 1
                g.FillEllipse(Brushes.Red, bezierPoints(i).X - 2, bezierPoints(i).Y - 2, 4, 4)
            Next
        End If
        PictureBox1.Image = g.Bitmap
    End Sub

    Private Sub RadioButton1_CheckedChanged(sender As Object, e As EventArgs) Handles RadioButton1.CheckedChanged
        '选择多边形模式
        mode = 0
        points.Clear()
        DrawPoints()
    End Sub

    Private Sub RadioButton2_CheckedChanged(sender As Object, e As EventArgs) Handles RadioButton2.CheckedChanged
        '选择基数样条模式
        mode = 1
        points.Clear()
        DrawPoints()
    End Sub

    Private Sub RadioButton3_CheckedChanged(sender As Object, e As EventArgs) Handles RadioButton3.CheckedChanged
        '选择贝赛尔曲线模式
        mode = 2
        points.Clear()
        bezierPoints.Clear()
        bezierCount = 0
        DrawPoints()
    End Sub

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        g = PictureBox1.CreateGraphics()
    End Sub
End Class

在这个示例程序中，我们在窗体上放置了三个RadioButton和一个PictureBox，RadioButton用于选择不同的绘制模式，PictureBox用于绘制图形。当用户在PictureBox上单击鼠标左键时，会添加一个点；当用户在PictureBox上单击鼠标右键时，会根据当前的模式来进行相应的操作。在绘制基数样条和贝赛尔曲线时，我们使用了.NET Framework提供的GraphicsPath类和DrawBezier方法来绘制曲线。