可以生成柱状图,曲线图,饼状图的自定义控件

using System;
using System.Web.UI;
using System.Data;
using System.Web.UI.WebControls;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Web;
using System.ComponentModel;
using System.Collections;

namespace hya.Control
{
    /// <summary>
    ///    柱状图控件
    ///    需要传入列表项名，值，超级连接地址
    /// </summary>
    [ToolboxData("<{0}:Columniation runat=server></{0}:Columniation>")]
    public class Columniation : System.Web.UI.WebControls.WebControl
    {
        private const int _colorLimit = 12;  //颜色列表
        private Color[] _color = 
        { 
            Color.Chocolate,
            Color.YellowGreen,
            Color.Olive,
            Color.DarkKhaki,
            Color.Sienna,
            Color.PaleGoldenrod,
            Color.Peru,
            Color.Tan,
            Color.Khaki,
            Color.DarkGoldenrod,
            Color.Maroon,
            Color.OliveDrab
       };

        private DataTable items;//列表项名称和值
        private string text = "数据";
        private string datastd = "标准值";
        private string data = "实时数据";

        int kds = 10; //刻度数
        float kddw = 100;  //没刻度大小
        int zmheight = 500; //真个图区高
        int zmwidth = 740;  //真个图区宽
        int height = 400;//呈现区高
        int width = 730;//呈现区宽
        int cxtop = 30;//呈现区距顶距离
        int cxleft = 30;//呈现区左边距离

        Color bzlink = Color.Black;//标准线颜色
        int Chart_Flag = 1;
        Bitmap bm;
        int Displacement = 0; //获取负坐标刻度数

        [Bindable(true),
        Category("Appearance"),
        DefaultValue("")]

        public string Text
        {
            get
            {
                return text;
            }
            set
            {
                text = value;
            }
        }

        [Bindable(true),
        Category("Appearance"),
        DefaultValue("")]

        public string DataStdName
        {
            get
            {
                return datastd;
            }
            set
            {
                datastd = value;
            }
        }

        [Bindable(true),
        Category("Appearance"),
        DefaultValue("")]

        public string DataName
        {
            get
            {
                return data;
            }
            set
            {
                data = value;
            }
        }

        /// <summary>
        /// 需要呈现的数据
        /// </summary>
        public DataTable Items
        {
            set
            { items = value; }
        }

        /// <summary>
        /// 需要显示的刻度量
        /// </summary>
        public int Kdcount
        {
            set { kds = value; }
        }

        /// <summary>
        /// 刻度大小
        /// </summary>
        public float Kddw
        { set { kddw = value; } }

        /// <summary>
        /// 1 为柱状,2 为折线,３为屏状
        /// </summary>
        public int ChatStyle
        { set { this.Chart_Flag = value; } }

        /// <summary> 
        /// 将此控件呈现给指定的输出参数。
        /// </summary>
        /// <param text="output"> 要写出到的 HTML 代码 </param>
        protected override void Render(HtmlTextWriter output)
        {
            //if(dt==null)
            //{
            // return "没有数据";
            //}
            //设计样式
            kd(items);
            output.Write(makeimage(items, "c:/"));
        }

        private string makeimage(DataTable dt, string imagefile)
        {
            string url = "";
            switch (Chart_Flag)
            {
                case 1:
                    this.Draw_X_Y_Bar(dt);
                    url = this.Drar_Bar(dt);
                    break;
                case 2:
                    this.Draw_X_Y(dt);
                    url = this.Drow_Lin(dt);
                    break;
                case 3:
                    url = this.Draw_Pie(dt);
                    break;
            }
            return url;
        }

        /// <summary>
        /// 换算成实际值
        /// </summary>
        /// <param text="kd">提供的值</param>
        /// <returns>返回换算后的实际值</returns>
        private float bl(float kd)
        {
            float bls = 1;
            bls = (float)height / ((float)kds * (float)kddw);
            return (float)kd * bls;
        }

        #region 通过数据计算刻度,和负坐标数
        private void kd(DataTable dt)
        {
            float mintest = float.MaxValue;
            float maxtest = float.MinValue;
            float maxnegative = 0f;

            for (int j = 1; j < dt.Columns.Count; j++)
            {
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    float test = System.Convert.ToSingle(dt.Rows[i][j]);
                    //求最小值
                    if (test < 0 && test < maxnegative)
                    {
                        maxnegative = test;
                    }
                    //求最大值
                    if (test > maxtest)
                    {
                        maxtest = test;
                    }
                }
            }

            maxtest = maxtest + Math.Abs(maxnegative);
            kddw = maxtest / kds;
            double exp = Convert.ToDouble(Math.Floor(Math.Log10(maxtest)));
            float tempMax = Convert.ToSingle(Math.Ceiling(maxtest / Math.Pow(10, exp)) * Math.Pow(10, exp));
            kddw = tempMax / kds;
            double expTick = Convert.ToDouble(Math.Floor(Math.Log10(kddw)));
            kddw = Convert.ToSingle(Math.Ceiling(kddw / Math.Pow(10, expTick)) * Math.Pow(10, expTick));
            this.Displacement = Math.Abs((int)Math.Floor(maxnegative / kddw));
        }
        #endregion

        #region  绘制折线图
        private string Drow_Lin(DataTable dt)
        {
            //通过循环画出曲线图   
            int x = -1;
            int bzy = -1;
            Graphics bp = Graphics.FromImage(bm);
            for (int j = 1; j < dt.Columns.Count; j++)
            {
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    //标准刻度
                    float bzkd = bl(System.Convert.ToSingle(dt.Rows[i].ItemArray[j]));
                    //实际刻度
                    // float sjkd=bl(System.Convert.ToSingle(dt.Rows[i].ItemArray[2]));
                    int bztop = cxtop + height - (int)bzkd - 3 - (int)(bl(this.Displacement * kddw));
                    //填充标准柱(画刷，起点Ｘ，起点Ｙ，宽，高）
                    bp.FillRectangle(new SolidBrush(_color[j - 1]), (i * 40) + cxleft + 20 - 3, bztop, 6, 6);
                    // int sstop=zmheight-(int)sjkd-(zmheight-cxtop-height)-3;
                    //填充实时点(画刷，起点Ｘ，起点Ｙ，宽，高）
                    // bp.FillRectangle(new SolidBrush(ss),(i*30)+cxleft,sstop,6,6);
                    //绘制点到点连接线
                    if (x != -1)
                    {
                        //绘制标准点连接线
                        bp.DrawLine(new Pen(_color[j - 1], 1.6F), new Point(x, bzy), new Point((i * 40) + cxleft + 20, bztop));
                        //绘制实时点连接线
                        // bp.DrawLine(new Pen(ss,1.6F),new Point(x+3,ssy+4),new Point((i*30)+cxleft+10,sstop+4));
                    }
                    x = (i * 40) + cxleft + 20;
                    bzy = bztop;
                }
                x = -1;
            }

            FileStream fs = new FileStream(Page.Server.MapPath(Page.Request.Url.AbsolutePath.Replace(".aspx", ".jpg")), FileMode.Create);
            bm.Save(fs, ImageFormat.Jpeg);
            bm.Dispose();
            bp.Dispose();
            fs.Close();
            return "<img src=" + Page.Request.Url.AbsolutePath.Replace(".aspx", ".jpg") + " ></img>";
        }
        #endregion

        #region 画住状图
        //画住状图　
        private string Drar_Bar(DataTable dt)
        {
            Graphics bp = Graphics.FromImage(bm);
            int flag = 0;
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                for (int j = 1; j < dt.Columns.Count; j++)
                {
                    float sjkd = bl(System.Convert.ToSingle(dt.Rows[i].ItemArray[j]));
                    float top = cxtop + height - (int)sjkd - (int)(bl(this.Displacement * kddw));
                    if (sjkd < 0)
                    {
                        top = top + sjkd;
                        sjkd = Math.Abs(sjkd);
                    }
                    bp.FillRectangle(new SolidBrush(this._color[j]), (flag * 40) + cxleft + 20, top, 20, sjkd);
                    flag++;
                }
            }
            FileStream fs = new FileStream(Page.Server.MapPath(Page.Request.Url.AbsolutePath.Replace(".aspx", ".jpg")), FileMode.Create);
            bm.Save(fs, ImageFormat.Jpeg);
            bm.Dispose();
            bp.Dispose();
            fs.Close();
            return "<img src=" + Page.Request.Url.AbsolutePath.Replace(".aspx", ".jpg") + " ></img>";
        }
        #endregion

        #region  画　X,Y 轴 线和刻度
        private void Draw_X_Y(DataTable dt)
        {
            //调整宽度
            width = 45 * dt.Rows.Count + 30;
            zmwidth = width + cxleft + 80;
            //创建一个画布
            bm = new Bitmap(zmwidth, zmheight);
            //在新建的画布上画一个图
            Graphics bp = Graphics.FromImage(bm);
            bp.Clear(Color.AliceBlue);
            //填充图表呈现区背景(画刷,起点x，起点Y，高，宽)
            bp.FillRectangle(new SolidBrush(Color.WhiteSmoke), cxleft, cxtop, width, height);
            //描绘呈现区边框
            bp.DrawRectangle(Pens.Black, cxleft, cxtop, width, height);
            //绘制图表名称
            bp.DrawString(text, new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(zmwidth / 2, 10));
            //绘制图表说明
            bp.DrawRectangle(Pens.Black, cxleft + width + 10, zmheight / 2, 60, 15 * dt.Columns.Count - 1);

            for (int j = 0; j < dt.Columns.Count - 1; j++)
            {
                bp.FillRectangle(new SolidBrush(this._color[j]), cxleft + width + 10 + 2, zmheight / 2 + 6 + 16 * j, 8, 8);
                //文字说明
                bp.DrawString(dt.Columns[j + 1].ColumnName, new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(cxleft + width + 10 + 2 + 8, zmheight / 2 + 4 + j * 12));
            }

            //通过循环绘制标准线
            for (int i = 0; i <= kds; i++)
            {
                string Cur_Kd;
                if (i - this.Displacement != 0)
                {
                    Cur_Kd = ((i - this.Displacement) * (kddw)).ToString("#,###.##");
                }
                else
                {
                    Cur_Kd = "0";
                }

                bp.DrawString(Cur_Kd, new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(2, zmheight - (bl(i * kddw) + (zmheight - cxtop - height) + 4)));
                //填充标准线(画刷，起点Ｘ，起点Ｙ，宽，高）
                int top = cxtop + height - (int)(bl(i * kddw));
                bp.DrawLine(new Pen(bzlink), new Point(cxleft - 4, top), new Point(cxleft + width, top));
            }

            for (int j = 1; j < dt.Rows.Count + 1; j++)
            {
                bp.DrawLine(new Pen(bzlink), new Point(cxleft + j * 40, (int)(cxtop + height - bl(this.Displacement * kddw))), new Point(cxleft + j * 40, (int)(cxtop + height - bl(this.Displacement * kddw)) + 4));
                bp.DrawString(dt.Rows[j - 1].ItemArray[0].ToString(), new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(((j - 1) * 40) + cxleft + 10, (int)(cxtop + height - bl(this.Displacement * kddw)) + 1));
            }
        }
        #endregion

        #region 画　柱状 x,y 　刻度
        private void Draw_X_Y_Bar(DataTable dt)
        {
            //调整宽度
            width = 45 * dt.Rows.Count * (dt.Columns.Count - 1) + 10;
            zmwidth = width + cxleft + 80;
            //创建一个画布
            bm = new Bitmap(zmwidth, zmheight);
            //在新建的画布上画一个图
            Graphics bp = Graphics.FromImage(bm);
            bp.Clear(Color.AliceBlue);
            //填充图表呈现区背景(画刷,起点x，起点Y，高，宽)
            bp.FillRectangle(new SolidBrush(Color.WhiteSmoke), cxleft, cxtop, width, height);
            //描绘呈现区边框
            bp.DrawRectangle(Pens.Black, cxleft, cxtop, width, height);
            //绘制图表名称
            bp.DrawString(text, new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(zmwidth / 2, 10));
            //绘制图表说明
            bp.DrawRectangle(Pens.Black, cxleft + width + 10, zmheight / 2, 60, 15 * dt.Columns.Count - 1);

            for (int j = 1; j < dt.Columns.Count; j++)
            {
                bp.FillRectangle(new SolidBrush(this._color[j]), cxleft + width + 10 + 2, zmheight / 2 + 6 + 16 * (j - 1), 8, 8);
                //文字说明
                bp.DrawString(dt.Columns[j].ColumnName, new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(cxleft + width + 10 + 2 + 8, zmheight / 2 + 6 + 16 * (j - 1)));
            }
            //通过循环绘制标准线
            for (int i = 0; i <= kds; i++)
            {
                string Cur_Kd;
                if (i - this.Displacement != 0)
                {
                    Cur_Kd = ((i - this.Displacement) * (kddw)).ToString("#,###.##");
                }
                else
                {
                    Cur_Kd = "0";
                }

                bp.DrawString(Cur_Kd, new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(2, zmheight - (bl(i * kddw) + (zmheight - cxtop - height) + 4)));
                //填充标准线(画刷，起点Ｘ，起点Ｙ，宽，高）
                int top = cxtop + height - (int)(bl(i * kddw));
                bp.DrawLine(new Pen(bzlink), new Point(cxleft - 4, top), new Point(cxleft + width, top));
            }

            if (dt.Columns.Count == 2)
            { }
            else
            {
                for (int j = 1; j < dt.Rows.Count + 1; j++)
                {
                    bp.DrawLine(new Pen(bzlink), new Point(cxleft + (dt.Columns.Count - 1) * j * 40, (int)(cxtop + height - bl(this.Displacement * kddw))), new Point(cxleft + (dt.Columns.Count - 1) * j * 40, (int)(cxtop + height - bl(this.Displacement * kddw)) + 12));
                    bp.DrawString(dt.Rows[j - 1].ItemArray[0].ToString(), new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(((dt.Columns.Count - 1) * (j - 1) * 40) + cxleft + 40, (int)(cxtop + height - bl(this.Displacement * kddw)) + 1));
                }
            }
        }
        #endregion

        #region  饼状图
        private string Draw_Pie(DataTable dt)
        {
            int width = 240;
            const int page_top_margin = 15;
            float total = 0.0F, tmp;
            int i;
            for (i = 0; i < dt.Rows.Count; i++)
            {
                tmp = Convert.ToSingle(dt.Rows[i][1]);
                total += tmp;

            }
            Font fontLegend = new Font("Verdana", 10);
            Font fontTitle = new Font("Verdana", 12, FontStyle.Bold);
            int titleHeight = fontTitle.Height + page_top_margin;
            int row_gap = 6;
            int start_of_rect = 8;
            int rect_width = 14;
            int rect_height = 16;
            int row_height;
            if (rect_height > fontLegend.Height) row_height = rect_height; else row_height = fontLegend.Height;
            row_height += row_gap;
            int legendHeight = row_height * (dt.Rows.Count + 1);
            int height = width + legendHeight + titleHeight + page_top_margin;
            int pieHeight = width;
            Rectangle pieRect = new Rectangle(0, titleHeight, width, pieHeight);
            float currentDegree = 0.0F;
            Bitmap bm = new Bitmap(width, height);
            Graphics objGraphics = Graphics.FromImage(bm);
            SolidBrush blackBrush = new SolidBrush(Color.Black);
            objGraphics.FillRectangle(new SolidBrush(Color.White), 0, 0, width, height);
            for (i = 0; i < dt.Rows.Count; i++)
            {
                objGraphics.FillPie(
                  new SolidBrush(this._color[i]),
                  pieRect,
                  currentDegree,
                  Convert.ToSingle(dt.Rows[i][1]) / total * 360);
                  currentDegree += Convert.ToSingle(dt.Rows[i][1]) / total * 360;
            }

            StringFormat stringFormat = new StringFormat();
            stringFormat.Alignment = StringAlignment.Center;
            stringFormat.LineAlignment = StringAlignment.Center;
            objGraphics.DrawString(this.datastd, fontTitle, blackBrush, new Rectangle(0, 0, width, titleHeight), stringFormat);
            objGraphics.DrawRectangle(new Pen(Color.Gray, 1), 0, height - legendHeight, width - 4, legendHeight - 1);
            int y = height - legendHeight + row_gap;
            for (i = 0; i < dt.Rows.Count; i++)
            {
                objGraphics.FillRectangle(new SolidBrush(this._color[i]), start_of_rect, y, rect_width, rect_height);
                objGraphics.DrawString(Convert.ToString(dt.Rows[i][0]) + " - " + Convert.ToString(dt.Rows[i][1]), fontLegend, blackBrush, start_of_rect + rect_width + 4, y);
                y += rect_height + row_gap;
            }
            FileStream fs = new FileStream(Page.Server.MapPath(Page.Request.Url.AbsolutePath.Replace(".aspx", ".jpg")), FileMode.Create);
            bm.Save(fs, ImageFormat.Jpeg);
            bm.Dispose();
            objGraphics.Dispose();
            fs.Close();
            return "<img src=" + Page.Request.Url.AbsolutePath.Replace(".aspx", ".jpg") + " ></img>";
        }
        #endregion
    }
}

在调用时很简单, 首先将它编译成控件,在aspx页添加引用
 

<%@ Register TagPrefix="cc1" Namespace="hya.Control" Assembly="Columniation" %>

在你需要显示图表的地方添加如下标签:

<cc1:Columniation id="Columniation1" runat="server"></cc1:Columniation>

在对应的.cs页写下如下的代码

 

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page
{
    private void Page_Load(object sender, System.EventArgs e)
    {
        // 在此处放置用户代码以初始化页面
        DataTable dt = new DataTable();
        DataColumn dc;
        dc = new DataColumn();
        dc.DataType = System.Type.GetType("System.String");
        dc.ColumnName = "name";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.DataType = System.Type.GetType("System.Int32");
        dc.ColumnName = "db";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.DataType = System.Type.GetType("System.Int32");
        dc.ColumnName = "df";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.DataType = System.Type.GetType("System.Int32");
        dc.ColumnName = "dz";
        dt.Columns.Add(dc);

        DataRow dr = dt.NewRow();
        dr["name"] = "点1";
        dr["db"] = "1000";
        dr["df"] = "500";
        dr["dz"] = "240";
        dt.Rows.Add(dr);

        dr = dt.NewRow();
        dr["name"] = "点2";
        dr["db"] = "200";
        dr["df"] = "200";
        dr["dz"] = "240";
        dt.Rows.Add(dr);

        dr = dt.NewRow();
        dr["name"] = "点3";
        dr["db"] = "300";
        dr["df"] = "600";
        dr["dz"] = "240";
        dt.Rows.Add(dr);

        dr = dt.NewRow();
        dr["name"] = "点4";
        dr["db"] = "200";
        dr["df"] = "1500";
        dr["dz"] = "240";
        dt.Rows.Add(dr);

        dr = dt.NewRow();
        dr["name"] = "点5";
        dr["db"] = "400";
        dr["df"] = "2400";
        dr["dz"] = "240";
        dt.Rows.Add(dr);

        Columniation1.Items = dt;
        Columniation1.ChatStyle = 3;  //1 为柱状,2 为折线,３为屏状 
    }
}

其生成的饼状图如下:

 

其生成的柱状图如下:

其生成的折线图如下: