C# Chart 折線圖 多條數據展示

private void btn_Click(object sender, EventArgs e)
{

        DBHelper db = new DBHelper();
        DataSet ds = db.GetDataList();
        this.dataGridView1.DataSource = ds.Tables[0];

        DataSet ds1 = db.GetResportLine();
        DataSet ds2 = db.GetResportLine2();
        DataSet ds3 = db.GetResportLine3();

        DataTable dt1 = ds1.Tables[0];
        DataTable dt2 = ds2.Tables[0];
        DataTable dt3 = ds3.Tables[0];
         
        //chart1.ChartAreas[0].AxisX.Maximum = 1000;//設定x軸的最大值
        //chart1.ChartAreas[0].AxisY.Maximum = 100;//設定y軸的最大值

        //chart1.ChartAreas[0].AxisX.Minimum = 1;//設定x軸的最小值
        //chart1.ChartAreas[0].AxisY.Minimum = 0;//設定y軸的最小值

        //第一條數據
        Series ss = new Series("dt1");   //這里 dt1 ,dt2 任意取名稱，但要唯一
        ss.Points.DataBind(dt1.AsEnumerable(), "xzhou", "yzhou", "");
        ss.XValueType = ChartValueType.DateTime; //設置X軸
        ss.ChartType = SeriesChartType.Spline;   //設置Y軸為折線
        chart1.Series.Add(ss);

        //第二條數據
        Series ss2 = new Series("dt2");
        ss2.Points.DataBind(dt2.AsEnumerable(), "xzhou2", "yzhou2", "");
        ss2.XValueType = ChartValueType.DateTime; //設置X軸
        ss2.ChartType = SeriesChartType.Spline;   //設置Y軸為折線
        chart1.Series.Add(ss2);

        //第三條數據
        Series ss3 = new Series("dt3");
        ss3.Points.DataBind(dt3.AsEnumerable(), "xzhou2", "yzhou2", "");
        ss3.XValueType = ChartValueType.DateTime; //設置X軸
        ss3.ChartType = SeriesChartType.Spline;   //設置Y軸為折線
        chart1.Series.Add(ss3);
         
    }