可以生成
柱状图,曲线图,饼状图,只要你给他一个datatable,在这声明一下
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;
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; } }



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;
}



//通过数据计算刻度,和负坐标数#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);

// this.Page .Response .Write (maxtest);

kddw = maxtest / kds;





double exp = Convert.ToDouble(Math.Floor(Math.Log10(maxtest)));

// this.Page .Response .Write ("exp"+exp.ToString ()+"<br>");
float tempMax = Convert.ToSingle(Math.Ceiling(maxtest / Math.Pow(10, exp)) * Math.Pow(10, exp));

// this.Page .Response .Write ("temp_Max"+exp.ToString ()+"<br>");


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));
// this.Page .Response.Write (this.Displacement);


}

#endregion



//

绘制折线图#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;
// ssy=sstop;
// bp.DrawString(dt.Rows[i].ItemArray[0].ToString (),new Font("宋体",9),new SolidBrush(Color.Black),new PointF((i*40)+cxleft+10,height+cxtop+1));


}

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




画住状图#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);

// this.Page .Response .Write ("<br>"+ (flag*40+cxleft+20) );

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




画 X,Y 轴 线和刻度#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("#,###.##");
// this.Page .Response .Write ("<br>abc"+Cur_Kd.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



画 柱状 x,y 刻度#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));
// this.Page .Response .Write ("<br>abc"+Cur_Kd.ToString ());
}
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


饼状图#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, // x
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: