C#折线图

    public void Draw_Curve(PointPairList list)        {            Random ran = new Random();            this.myPane.GraphPane.Title = "动态折线图";            this.myPane.GraphPane.XAxis.Title = "时间";            this.myPane.GraphPane.YAxis.Title = "数量";            this.myPane.GraphPane.XAxis.Type = ZedGraph.AxisType.Date;            this.myPane.GraphPane.CurveList.Clear();            /*double[] x = new double[length];            double[] y = new double[length];                       for (int i = 0; i < length; i++)            {                x[i] = (double)new XDate(DateTime.Now.AddSeconds((-(length - i))));                double temp = (double)i / length * Math.PI * 2.0;                y[i] = Math.Sin(temp) + 1.5;                //y[i] = ran.NextDouble();             //   list.Add(x, y);            }*/           // z1.GraphPane.Draw("Sine Wave", x, y, Color.Red, SymbolType.None);            myPane.GraphPane.AddCurve("Sine Wave", list, Color.Red, SymbolType.Circle);            myPane.AxisChange();            myPane.Invalidate();        }private void Form1_Load( object sender, System.EventArgs e ){            //Draw_Curve(400);/*z1.IsShowPointValues = true;z1.GraphPane.Title = "Test Case for C#";double[] x = new double[100];double[] y = new double[100];inti;for ( i=0; i<100; i++ ){               // x[i] = i;x[i] = (double) i / 100.0 * Math.PI * 2.0;y[i] = Math.Sin( x[i] )+1.5;}z1.GraphPane.AddCurve( "Sine Wave", x, y, Color.Red, SymbolType.None );z1.AxisChange();z1.Invalidate();*/}        //输入参数：最后的时间，总点数，实际的点数，数值        public PointPairList Convert_Point(string[] time,double[] data,int total,int count)        {            int i=0;            PointPairList list = new PointPairList();            DateTime dtime = Convert.ToDateTime(time[0]);       //获得第一个点的时间值            if (count > total)            {                Console.WriteLine("count>total");                return list;            }            for (i = 0; i < total-count; i++)      //点数不够，补0            {                double x = (double)new XDate(dtime.AddSeconds(-((total - count - i) * 2)));                double y = 0;                list.Add(x,y);            }            for (i = 0; i < count; i++)            {                dtime = Convert.ToDateTime(time[i]);                double x = (double)new XDate(dtime);                double y = data[i];                list.Add(x,y);            }            return list;        }        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)        {            int selected_index = this.comboBox1.SelectedIndex;            int point_count = 5;            double[] x = new double[2000];            double[] y = new double[2000];            for (int i = 0; i < 2000; i++)            {                x[i] = (double)new XDate(DateTime.Now.AddSeconds(i));                double temp = (double)i / 1000 * Math.PI * 2.0;                y[i] = Math.Sin(temp) + 1.5;            }            //this.z1.            switch (selected_index)            {                case 0:     //1                    point_count = 1;                    break;                case 1:     //5                    point_count = 5;                    break;                case 2:     //10                    point_count = 10;                    break;                case 3:     //20                    point_count = 20;                    break;                case 4:     //30                    point_count = 30;                    break;                case 5:     //60                    point_count = 60;                    break;                default:                    break;            }            int total = point_count * 30;   //要显示的总点数            int len=(int)(total);       //实际的总点数            string[] xx = new string[len];            double[] yy = new double[len];            string time_str = "2012-12-11 13:57:20";            DateTime time =Convert.ToDateTime(time_str);            //Console.WriteLine(time1.ToString());            for (int i = 0; i < len; i++)            {                xx[i] = time.AddSeconds(i*2).ToString();                yy[i] = y[i];            }            PointPairList list = Convert_Point(xx,yy,total,len);            Draw_Curve(list);        }