GDI画线时去除y=0的点也就是画不连接的线的问题请问怎么实现

lrose0716 2010-10-20 11:55:48

我是用GDI画的想把15-20这几个点去掉也就是当y=0时就不要画线不为0时继续图上的点我没对准所以看着不为0 请问这个要怎么实现。
下面是我的代码

private void CreateImage()

    {

        int height = 500, width = 1000;

        Bitmap image = new Bitmap(width, height);

        Graphics g = Graphics.FromImage(image);

        Pen mypen = new Pen(System.Drawing.Color.Blue, 1);

        g.FillRectangle(Brushes.WhiteSmoke, 0, 0, width, height);

        int x = 50;

        for (int i = 0; i < 24; i++)

        {

            g.DrawLine(mypen, x, 0, x, 338);

            x = x + 40;

        }

        int y = 0;

        for (int i = 0; i < 14; i++)

        {

            g.DrawLine(mypen, 50, y, 970, y);

            y = y + 26;

        }

        String[] m = {"325","300","275", "250", "225", "200", "175", "150", "125", "100" ,"75","50","25",""};

      

        Font font = new Font("Verdana", 12);

        x = 35;

        for (int i = 0; i < 24; i++)

        {

            g.DrawString(i.ToString(), font, Brushes.Blue, x, 338);

            x = x + 40;

        }

        y = -5;

        for (int i = 0; i < 14; i++)

        {

            g.DrawString(m[i].ToString(), font, Brushes.Blue, 15, y);

            y = y + 26;

        }



        SqlConnection Con = new SqlConnection("Server=(Local);Database=test;Uid=sa;Pwd=rose");

        Con.Open();

        string cmdtxt2 = "select * from test";

        SqlDataAdapter da = new SqlDataAdapter(cmdtxt2, Con);

        DataSet ds = new DataSet();

        da.Fill(ds,"Result");

        DataTable dt = ds.Tables["Result"];

        Point[] point = new Point[23];

        Pen mypen3 = new Pen(Color.Green, 2);

       

        for (int k = 0; k < dt.Rows.Count; k++)

        {

            

                point[k] = Points(int.Parse(dt.Rows[k]["time"].ToString()), int.Parse(dt.Rows[k]["value"].ToString()));

               

        

        

        }

       



        g.DrawLines(mypen3, point);

        







        System.IO.MemoryStream ms = new

        System.IO.MemoryStream();

        image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

        Response.ClearContent();

        Response.ContentType = "image/Jpeg";

        Response.BinaryWrite(ms.ToArray());













    }

    Point Points(int x,int y)

    {

       

            Point p = new Point();

            p.X = 50 + 40 * x;

            p.Y = 333 - y;

            return p;

       

        

    

    }