C# 如何在ASP.NET中用C突出显示样条曲线图中的最高和最低日期值

我正在为我的组织准备一张图表。我想用不同的颜色突出显示ASP中样条曲线图系列值中最高870和最低600的学生姓名/分数。使用C

表数据：

David 700
John  870
Neil  810
Robert 720
Andrew 600

代码隐藏：

protected void Page_Load(object sender, EventArgs e)
{
       DataBindingToChart();
}
public void DataBindingToChart()
{
        string Query = "select * from Student;";
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["DB_Connection"].ConnectionString);
        con.Open();
        DataSet ds = new DataSet();
        DataTable dt = new DataTable();
        SqlDataAdapter adp = new SqlDataAdapter(Query, con);
        adp.Fill(ds);
        dt = ds.Tables[0];
        string[] x = new string[dt.Rows.Count];
        int[] y = new int[dt.Rows.Count];
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            x[i] = dt.Rows[i][0].ToString();
            y[i] = Convert.ToInt32(dt.Rows[i][1]);
        }

        Chart1.Series[0].Points.DataBindXY(x, y);
        Chart1.Series[0].ChartType = SeriesChartType.Spline; // Here We Can Change Chart Type
        Chart1.Series[0].Color = Color.Cyan;
        Chart1.Series[0].BorderColor = Color.Black;
        Chart1.Series[0].BorderWidth = 5;
        Chart1.Series[0].MarkerStyle = MarkerStyle.Circle;
        Chart1.Series[0].MarkerBorderWidth = 5;
        Chart1.Legends[0].Enabled = false;
        Chart1.Series[0].IsValueShownAsLabel = true;
        Chart1.ChartAreas["ChartArea1"].Area3DStyle.Enable3D = false;
        Chart1.ChartAreas["ChartArea1"].AxisX.MajorGrid.Enabled = false;
        Chart1.ChartAreas["ChartArea1"].AxisY.MajorGrid.Enabled = false;
        Chart1.ChartAreas["ChartArea1"].AxisX.Interval = 1;
        Chart1.ChartAreas["ChartArea1"].AxisX.LabelStyle.Angle = -90;
        Chart1.ChartAreas["ChartArea1"].AxisX.LabelStyle.Font = new Font("Calibri", 12f, System.Drawing.FontStyle.Bold);
        Chart1.ChartAreas["ChartArea1"].AxisX.LabelStyle.ForeColor = Color.DeepPink;
        Chart1.ChartAreas["ChartArea1"].AxisY.LabelStyle.Font = new Font("Calibri", 12f, System.Drawing.FontStyle.Bold);
        Chart1.ChartAreas["ChartArea1"].AxisY.LabelStyle.ForeColor = Color.Green;
        Chart1.ChartAreas["ChartArea1"].AxisX.Title = "Students";
        Chart1.ChartAreas["ChartArea1"].AxisX.TitleAlignment = StringAlignment.Center;
        Chart1.ChartAreas["ChartArea1"].AxisX.TitleForeColor = Color.DarkBlue;
        Chart1.ChartAreas["ChartArea1"].AxisX.TitleFont = new Font("Calibri", 16f, System.Drawing.FontStyle.Bold);
        Chart1.ChartAreas["ChartArea1"].AxisY.Title = "Marks";
        Chart1.ChartAreas["ChartArea1"].AxisY.TitleAlignment = StringAlignment.Center;
        Chart1.ChartAreas["ChartArea1"].AxisY.TitleForeColor = Color.Orange;
        Chart1.ChartAreas["ChartArea1"].AxisY.TitleFont = new Font("Calibri", 16f, System.Drawing.FontStyle.Bold);
        con.Close();
}