asp.net下使用C#实现动态绘制图表

最近一直在做毕业设计，大体上是一个信息管理系统。关键的功能是实现一些简单的统计分析，所以要在网页中加一些图表显得清晰直观一些。那么既然完成了，那就简单总结一下，也算对得起这个项目了。估计上去以后也很少在接触asp.net，感觉asp.net还是一门非常有发展前景且方便的技术，只是对其还是有太多的限制和歧视存在。

/*****************************************此处开始正文,前方自动无视**************************************/

BS结构的程序最头疼的就是web报表的制作，虽然有水晶报表这一控件。

但是那是付费的，要正版啊亲，再说了我们只是实现简单的功能有木有，所以不用那么复杂吧。

总之，本文的目的是通过C#提供的System.Drawing2D下的绘图类动态生成报表。

项目中一共用到了饼图和折现图，所以也就实现了这两个图形的回执功能。

先来看看类图：



先放上GraphicBase类和IGraphic的接口：

/************************************************
**GraphicBase.cs
**绘图基类，实现动态图表的绘制
**编译环境：VS2010,Windows7 C#4.0
**2012-5-18
**************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;

namespace Graphic
{
public  abstract class GraphicBase
{
#region Properties
public String Title
{
get { return this._titletxt; }
set { this._titletxt = value; }
}
public int Width
{
get { return this._width; }
set { this._width = value; }
}
public int Height
{
get { return this._height;  }
set { this._height = value; }
}
public Font TitleFont
{
get { return this._titlefont; }
set { this._titlefont = value; }
}
public Font TxtFont
{
get { return this._txtfont; }
set { this._txtfont = value; }
}
public Color BKColor
{
get { return this._bkcolor; }
set { this._bkcolor = value; }
}
#endregion

#region Fields
protected int _width;
protected int _height;
protected String _titletxt;
protected Font _titlefont;
protected Font _txtfont;
protected Color _bkcolor=Color.White;
protected Bitmap _image;
protected Graphics _g;
#endregion

#region Methods
protected virtual void intiGraphic()
{
this._image = new Bitmap(_width, _height);
this._g = Graphics.FromImage(this._image);
}
public virtual void setBkgColor()
{
this._g.FillRectangle(
new SolidBrush(BKColor), 0, 0, _width, _height);
}
public virtual void setFont()
{
this._txtfont= new Font("verdana", 9);
this._titlefont = new
Font("verdana", 10, FontStyle.Bold);
}
public virtual System.IO.MemoryStream getGraphic()
{
System.IO.MemoryStream ms =
new System.IO.MemoryStream();
_image.Save(ms,
System.Drawing.Imaging.ImageFormat.Gif);
return ms;
}

protected virtual void drawTitle() { }
protected virtual void drawIdentification() { }
protected virtual void drawGraphic() { }
#endregion
}
}

/************************************************
**IGraphic.cs
**绘图基类，实现动态图表的绘制
**编译环境：VS2010,Windows7 C#4.0
**2012-5-18
**************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Grphics
{
public interface IGraphic
{
//设置字体
void setFont();
//设置背景颜色
void setBkgColor();
//实现绘图操作
void doDraw();
//将绘制的图形以流的形式返回
System.IO.MemoryStream getGraphic();
}
}

下面将饼图的绘制代码贴上：

/************************************************
**PieGraphic.cs
**绘图基类，实现动态图表的绘制
**编译环境：VS2010,Windows7 C#4.0
**2012-5-18
**************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Collections;

namespace Grphics
{
public class PieGraphic:GraphicBase,IGraphic
{
//饼图数据类
public class pieData
{
#region Fields
private float _total=0;
private Dictionary<String,float>_parts=
new Dictionary<string,float>();
#endregion
#region Properties
public float Total
{
get { return this._total; }
set { this._total = value; }
}
public Dictionary<String, float> Parts
{
get { return this._parts; }
set { this._parts = value; }
}
#endregion
#region Methods
public void addPart(String text,float value)
{
this.Parts.Add(text,value);
}
public void removePart(String text)
{
this.Parts.Remove(text);
}
#endregion
}
#region Fields
private int _diameter;
private pieData _data;
private Rectangle _pierect;
private ArrayList _colors=new ArrayList();
#endregion
#region Properties
//饼图周长
public int Diameter
{
get { return this._diameter; }
set { this._diameter = value; }
}
public pieData PieData
{
get { return this._data; }
set { this._data = value; }
}
#endregion
#region Methods
public PieGraphic(pieData data, int diameter, String title)
{
this.Title = title;
this.Diameter = diameter;
this._data = data;
}
protected override void intiGraphic()
{
int bufferspace = 15;
int titleheight = this.TitleFont.Height + bufferspace;
this._height = _diameter + titleheight;
int lendwidth = _diameter * 2;
this._width = _diameter + lendwidth + bufferspace;
this._pierect =
new Rectangle(0, titleheight, _diameter, _diameter);
base.intiGraphic();
}
public override void setBkgColor()
{
//设置背景色
base.setBkgColor();
//给扇形图区域加上一个背景色
this._g.FillRectangle(new SolidBrush(Color.Beige), _pierect);
}
protected override void drawTitle()
{
//标题设置颜色，黑色和蓝色
SolidBrush blackbrush = new SolidBrush(Color.Black);
SolidBrush bluebrush = new SolidBrush(Color.Blue);
this.Title += "\n \n\n";
StringFormat stringFormat = new StringFormat();
stringFormat.Alignment = StringAlignment.Center;
stringFormat.LineAlignment = StringAlignment.Center;

int titleheight = 15 + TitleFont.Height;/*15=bufferspace*/
this._g.DrawString(Title, TitleFont, blackbrush,
new Rectangle(0, 20, _width, titleheight), stringFormat);
}
protected override void drawIdentification()
{
int count = 1;
int colum = 0;
int size = 8;
int tmp;
SolidBrush blackbrush = new SolidBrush(Color.Black);
List<float> list = new List<float>(_data.Parts.Values);
foreach (KeyValuePair<String, float> part in _data.Parts)
{
count++;
tmp = count % size;
if (count / size > 0)
tmp += 2;
_g.FillRectangle(
new SolidBrush(
(Color)_colors[count - 2]),
new Rectangle(
_diameter + 15 + colum * 200,
tmp * 30, 35, 15));
colum = count / size;
String str =
part.Key + ":" + part.Value +
" " +
(part.Value / _data.Total * 100).ToString() +
"%";
_g.DrawString(str,
TxtFont, blackbrush,
new PointF(_diameter + 50 + colum * 200, tmp * 30));
}
}
protected void getcolors()
{
Random rnd = new Random();
for (int i = 0; i < _data.Parts.Count(); i++)
_colors.Add(
Color.FromArgb(rnd.Next(255),
rnd.Next(255), rnd.Next(255)));
}
protected override void drawGraphic()
{
//当前位置
float currentAngle = 0.0f;
int count = 0;
foreach (KeyValuePair<String, float> part in _data.Parts)
{
//画出部分扇区
float part_degree =
part.Value / this._data.Total * 360.0f;
this._g.FillPie(
new SolidBrush(
(Color)_colors[count++]),
_pierect, currentAngle, part_degree);
currentAngle += part_degree;
}
}
public void doDraw()
{
try
{
this.getcolors();
this.setFont();
this.intiGraphic();
this.setBkgColor();
this.drawGraphic();
this.drawIdentification();
this.drawTitle();
}
catch (Exception ex)
{
ex.Message.ToString();
}
}
#endregion
}
}

下面使用法介绍：

protected void Page_Load(object sender, EventArgs e)
{
Dictionary<String, float> dic =
new Dictionary<string, float>();
dic.Add("test1",1);
dic.Add("test2",3);
dic.Add("test3",4);
dic.Add("test4",2);
float total=Convert.ToSingle(10);
String title="测试用饼图";
PieGraphic.pieData data =
new PieGraphic.pieData();
data.Parts = dic;
data.Total = total;
pie = new PieGraphic(data, 250, title);
Response.ClearContent();
Response.ContentType = "image/gif";
pie.doDraw();
byte[] bytes=pie.getGraphic().ToArray();
Response.BinaryWrite(bytes);
}

结果如下图：



累了，等下次有空再把折线图补全吧~~~~