ASP.NET动态创建柱状图与饼状图_.NET教程_编程技术--HTML5中文学习网

asp.net|饼状图|创建|动态|柱状图

做web项目开发，难免会遇到动态创建柱状图或饼型图。现在用.net技术实现动态的创建它们。由于本身比较喜欢足球，更是鲁能的球迷，所以就用了鲁能的主场球迷人数作为例子，请不要太惊奇

！一个人在西安的山东人希望鲁能可以提前夺冠！！呵呵，扯远了……

动态创建柱状图与饼状图的前台HTML代码如下：

<body>

<tr>

</tr>

<tr>

<td height="20" align="middle">ASP.NET 中动态创建图形范例</td>

</tr>

</table>

</form>

</body>

程序运行后的效果如图：

后台代码如下：

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;

using System.Drawing.Imaging; //添加 Imaging 的引用。

namespace WebApplication1

{

///<summary>

/// ChartText 的摘要说明。

/// 作者：Shadow

///</summary>

public class ChartText : System.Web.UI.Page

{

private void Page_Load(object sender, System.EventArgs e)

{

Bitmap objBitMap = new Bitmap(400, 240);

Graphics objGraphics;

objGraphics = Graphics.FromImage(objBitMap);

objGraphics.Clear(Color.White);

int[] arrValues = {40000,32000,24000,30000,36000,28000};

string[] arrValueNames = newstring[]{"第一次","第二次","第三次","第四次","第五次","第六次"};

objGraphics.DrawString(" 山东鲁能主场球迷人数统计（人）",

new Font("宋体", 16), Brushes.Blue, new PointF(5, 5));

PointF symbolLeg = new PointF(335, 20);

PointF descLeg = new PointF(360, 16);

//画出说明部分的图形

for (int i = 0; i < arrValueNames.Length; i++)

{

objGraphics.FillRectangle(new SolidBrush(GetColor(i)), symbolLeg.X, symbolLeg.Y, 20, 10);

objGraphics.DrawRectangle(Pens.Black, symbolLeg.X, symbolLeg.Y, 20, 10);

objGraphics.DrawString(arrValueNames[i].ToString(), new Font("宋体", 10), Brushes.Black, descLeg);

symbolLeg.Y += 15;

descLeg.Y += 15;

}

float TotalValues = 0;

for (int i = 0; i <= arrValues.Length - 1; i++)

{

TotalValues += arrValues[i];

}

//绘出矩形图。

float Rectangleheight = 0;

PointF recLeg = new PointF(12,200-arrValues[0]/TotalValues*300);

for (int i = 0; i < arrValues.Length; i++)

{

Rectangleheight = arrValues[i] / TotalValues *300;

objGraphics.FillRectangle(new SolidBrush(GetColor(i)), (i * 35) + 15, 200 - Rectangleheight, 20,

Rectangleheight + 50);

objGraphics.DrawRectangle(Pens.Black, (i * 35) + 15, 200 - Rectangleheight, 20, Rectangleheight + 50);

recLeg.Y=200-Rectangleheight-14;

objGraphics.DrawString(arrValues[i].ToString(), new Font("宋体", 10), Brushes.Blue, recLeg);

recLeg.X+=35;

}

//绘出圆形图。

float sglCurrentAngle = 0;

float sglTotalAngle = 0;

for (int i = 0; i < arrValues.Length; i++)

{

sglCurrentAngle = arrValues[i] / TotalValues * 360;

objGraphics.FillPie(new SolidBrush(GetColor(i)), 220, 95, 100, 100, sglTotalAngle, sglCurrentAngle);

objGraphics.DrawPie(Pens.Black, 220, 95, 100, 100, sglTotalAngle, sglCurrentAngle);

sglTotalAngle += sglCurrentAngle;

}

objBitMap.Save(Response.OutputStream, ImageFormat.Gif);

}

#region Web 窗体设计器生成的代码

override protected void OnInit(EventArgs e)

{

// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。

InitializeComponent();

base.OnInit(e);

}

///<summary>

/// 设计器支持所需的方法 - 不要使用代码编辑器修改

/// 此方法的内容。

///</summary>

private void InitializeComponent()

{

this.Load += new System.EventHandler(this.Page_Load);

}

#endregion

//定义颜色。

private Color GetColor(int itemIndex)

{

Color objColor;

if (itemIndex == 0)

{

objColor = Color.Maroon;

}

elseif (itemIndex == 1)

{

objColor = Color.Red;

}

elseif (itemIndex == 2)

{

objColor = Color.Gray;

}

elseif (itemIndex == 3)

{

objColor = Color.Blue;

}

elseif (itemIndex == 4)

{

objColor = Color.Orange;

}

elseif (itemIndex == 5)

{

objColor = Color.Cyan;

}

elseif (itemIndex == 6)

{

objColor = Color.Bisque;

}

elseif (itemIndex == 7)

{

objColor = Color.Maroon;

}

elseif (itemIndex == 8)

{

objColor = Color.Maroon;

}

else

{

objColor = Color.Blue;

}

return objColor;

}