c# 柱状图

// c# 显示柱状图

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Drawing.Imaging;

using System.Drawing; 

/// <summary>

/// DrawingCurve 的摘要说明

/// </summary>

public class DrawingCurve

{

    

    public int intXLong = 800;   //图片大小 长

    public int intYLong = 600;   //图片大小 高

    public int intXMultiple = 1;    //零刻度的值 X

    public int intYMultiple = 0;    //零刻度的值 Y

    public int intXMax = 12;    //最大刻度(点数) X

    public int intYMax = 30;    //最大刻度(点数) Y



    public int intLeft = 50;   //左边距

    public int intRight = 120; //右边距

    public int intTop = 30;    //上边距

    public int intEnd = 50;    //下边距



    public string strXText = "时间(单位:月)";    //单位 X

    public string strYText = "数量(单位:个)";    //单位 Y

    public string strTitle = "趋势线图";    //标题

    public DataTable tbData;    //要统计的数据





    private int intXScale = 30;    //一刻度长度 X

    private int intYScale = 30;    //一刻度高度 Y

    //private int intX = 0;   //0点 X坐标

    //private int intY = 0;   //0点 Y坐标

    public int intData = 0;    //记录数



    public DrawingCurve()

    {



        intXScale = (intXLong - intLeft - intRight) / (intXMax + 1);//一刻度长度 X

        intYScale = (intYLong - intTop - intEnd) / (intYMax + 1);//一刻度高度 Y



        //intX = intXLong - intLeft;   //0点 X坐标

        //intY = intYLong - intEnd;   //0点 Y坐标

    }



    public Bitmap DrawingImg()

    {



        Bitmap img = new Bitmap(intXLong, intYLong); //图片大小

        Graphics g = Graphics.FromImage(img);

        g.Clear(Color.Snow);

        g.DrawString(strTitle, new Font("宋体", 14), Brushes.Black, new Point(5, 5));

        g.DrawLine(new Pen(Color.Black, 2), intLeft, intYLong - intEnd, intXLong - intRight, intYLong - intEnd); //绘制横向

        g.DrawLine(new Pen(Color.Black, 2), intLeft, intTop, intLeft, intYLong - intEnd);   //绘制纵向



        //绘制纵坐标

        g.DrawString(strYText, new Font("宋体", 12), Brushes.Black, new Point(intLeft, intTop));//Y 单位

        Point p1 = new Point(intLeft - 10, intYLong - intEnd);

        for (int j = 0; j <= intYMax; j++)

        {

            p1.Y = intYLong - intEnd - j * intYScale;

            Point pt = new Point(p1.X + 10, p1.Y);

            //绘制纵坐标的刻度和直线

            g.DrawLine(Pens.Black, pt, new Point(p1.X + 15, p1.Y));

            //绘制纵坐标的文字说明

            g.DrawString(Convert.ToString(j + intYMultiple), new Font("宋体", 12), Brushes.Black, new Point(p1.X - 25, p1.Y - 8));

        }



        //绘制横坐标

        g.DrawString(strXText, new Font("宋体", 12), Brushes.Black, new Point(intXLong - intRight, intYLong - intEnd));//X 单位

        Point p = new Point(intLeft, intYLong - intEnd);

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

        {

            p.X = intLeft + i * intXScale;

            //绘制横坐标刻度和直线

            g.DrawLine(Pens.Black, p, new Point(p.X, p.Y - 5));

            //绘制横坐标的文字说明

            g.DrawString(Convert.ToString(i + intXMultiple), new Font("宋体", 12), Brushes.Black, p);

        }





        intData = tbData.Rows.Count;

        if (intData > 0)

        {

            //趋势线图

            for (int i = 0; i < intData - 1; i++)

            {

                DataRow Row1 = tbData.Rows[i];

                DataRow Row2 = tbData.Rows[i + 1];

                //定义起点

                Point rec = new Point(Convert.ToInt32(intLeft + ((TurnNumber(Row1[0].ToString()) - intXMultiple) * intXScale)), Convert.ToInt32(intYLong - intEnd - (TurnNumber(Row1[1].ToString()) - intYMultiple) * intYScale));

                //定义终点

                Point dec = new Point(Convert.ToInt32(intLeft + ((TurnNumber(Row2[0].ToString()) - intXMultiple) * intXScale)), Convert.ToInt32(intYLong - intEnd - (TurnNumber(Row2[1].ToString()) - intYMultiple) * intYScale));

                //绘制趋势折线

                g.DrawLine(new Pen(Color.Red), rec, dec);

            }

        }



        return img;

    }



    //转换数字

    private double TurnNumber(string str)

    {

        double dubReturn;

        try

        {

            dubReturn = Convert.ToDouble(str);

        }

        catch

        {

            dubReturn = 0;

        }

        return dubReturn;



    }



}



----------------------------------调用------------------------------------------------



protected void Page_Load(object sender, EventArgs e)

    {

        DataTable MyTable = new DataTable();

        



        string constr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("App_Data/db.mdb");

        string cmdstr = "SELECT 月份,销量 FROM Result";

        OleDbConnection con = new OleDbConnection(constr);

        con.Open();

        //OleDbCommand cmd = new OleDbCommand(cmdstr, con);

        OleDbDataAdapter da = new OleDbDataAdapter(cmdstr, con);

        da.Fill(MyTable);





        DrawingCurve MyDc = new DrawingCurve();

        MyDc.tbData = MyTable;



        Bitmap img = new Bitmap(100, 100);

        img = MyDc.DrawingImg();

        Graphics g = Graphics.FromImage(MyDc.DrawingImg());



        //显示图形

        img.Save(Response.OutputStream, ImageFormat.Jpeg);;

        g.Dispose();

        Response.Write("<br>" + MyDc.intData.ToString());

    }