C#画折线图

书上讲了折线图的画法，可惜没把坐标画好，整个图成了个表格图，只好自己到网上查资料来试验。

 private static Bitmap DrawCoordinate(Bitmap image, string[] ItemName, decimal[] ItemValue)
        {
            //坐标轴 
            Point P0 = new Point(60, 360);
            Point Px = new Point(420, 360);
            Point Py = new Point(60, 65);
            Pen pen = new Pen(Color.Black);
            //箭头 
            Point Py1 = new Point(58, 70);
            Point Py2 = new Point(62, 70);
            Point Px1 = new Point(415, 358);
            Point Px2 = new Point(415, 362);
            //Y,X Value 
            //y 280-10 
            int YCount = 10;//Y轴点的数量 
            int YDistance = Convert.ToInt32(280 / YCount);//Y轴点击的距离 
            int[] YValue = GetYValue(ItemValue, YCount);
            int len = 3;//短线的长度 
            int XCount = ItemName.Length;//X轴点的数量 
            int XDistance = Convert.ToInt32(350 / XCount);//X轴点间的距离 
            // 
            Font f = new Font("新宋体", 8, FontStyle.Bold);
            //Image 
            Graphics g = Graphics.FromImage(image);
            g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
            try
            {
                //绘制坐标轴线 
                g.DrawLine(pen, P0, Px);
                g.DrawLine(pen, P0, Py);
                //箭头 
                g.DrawLine(pen, Py, Py1);
                g.DrawLine(pen, Py, Py2);
                g.DrawLine(pen, Px, Px1);
                g.DrawLine(pen, Px, Px2);
                //X 
                for (int i = 1; i <= XCount; i++)
                {
                    Point pl1 = new Point(P0.X + i * XDistance, P0.Y);
                    Point pl2 = new Point(P0.X + i * XDistance, P0.Y - len);
                    string str = ItemName[i - 1];
                    Point ps = new Point(pl1.X - (str.Length * 8), pl1.Y + 5);
                    g.DrawLine(pen, pl1, pl2);
                    g.DrawString(str, f, new SolidBrush(Color.Black), ps);
                }
                //Y 
                for (int i = 1; i <= YCount; i++)
                {
                    Point pl1 = new Point(P0.X, P0.Y - YDistance * i);
                    Point pl2 = new Point(pl1.X + len, pl1.Y);
                    string str = YValue[i - 1].ToString();
                    Point ps = new Point(pl1.X - str.Length * 8, pl1.Y - 5);
                    g.DrawLine(pen, pl1, pl2);
                    g.DrawString(str, f, new SolidBrush(Color.Black), ps);
                }
                g.DrawString("0", f, new SolidBrush(Color.Black), new Point(P0.X - 10, P0.Y - 10));
                return image;
            }
            finally
            {
                g.Dispose();
            }
        } 

 Bitmap bmp = new Bitmap(500,400);
            Bitmap result = new Bitmap(500,400);
            Graphics g = Graphics.FromImage(bmp);
            string[] x = { "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17","18","19","20", "21", "22", "23", "24", "25", "26", "27", "28", "29","30"};

//横坐标的坐标值
             decimal[] y = {100,200,156,100,200,156,100,200,156};

//纵坐标的坐标值
            result = DrawCoordinate(bmp,x,y);
            result.Save(Environment.CurrentDirectory + "/week.bmp");