求助热心高人：GDI画线问题

Const num% = 299
k = num /3
        For λbc = PI / 2 To αStep   PI / （2*k）
            p(i) =  Sin(λbc)
            p(i + 1) = rd * Cos(λbc)/ Cos(βj)
            p(i + 2) = 0
              i = i + 3
        Next λbc
Dim cenp(100) As PointF
        Dim q As Double
        q = 0
        For i = 0 To 297 Step 3
            cenp(q).X = p(i)
          cenp(q).Y = p(i + 1)
           q = q + 1
        Next
       objgraphics.DrawLines(mypen, cenp)
程序是这样的， 想实现的就是通过前面的点画线，但是始终无法定义前面的点，无法实现功能，求高人看看  指点迷津