使用C#绘制图形引擎的Framework的方法

Batman
下面将推荐一个可以很方便的生成多种图形格式的，使用了ASP+技术的图形
引擎代码。它的主要描述如下：
1.可以生成的图形文件格式支持BMP
EMF，GIF，Icon，JPEG，PNG，TIFF，WMF
2.在文件ChartEngine.cs中为这个图形引擎的大量关键代码
StockPicker.aspx文件是一个使用该引擎绘图的例子
3.要使用这个图形引擎，需要把所有的代码文件复制到你的web的某个
运用目录（注：不是普通目录）中，然后在该目录下建立一个bin目录，
然后运行mk.bat
4.ImageGenerator_VB.asp文件的头使用了<%@ Page ContentType="image/jpeg"
%>来说明生成的是某种格式的图形文件
5.为了服务器性能考虑，还可以在ImageGenerator_VB.asp中增加以下代码
<%@ OutputCache Duration="60" %>，该代码可以将生成的图形文件缓存起来
这样如果网站访问量大时，可以大大减轻服务器的负担

好了，废话少说，大家可以自己研究研究代码：
1.ChartEngine.cs文件
using System.WinForms;
using System.Collections;
using System.Collections.Bases;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.ComponentModel;
using System;
using System.IO;

namespace ChartGenerator{
//Core Line Data structure
public struct LineData {
public float[] LineValues;
public string LineTitle ;
public string LineSymbol ;
}
//Line Data plus display style information
public class ChartLine {
private Color lineColor ;
private LineData lineData ;
private DashStyle lineStyle ;
private int lineWidth;
//Constructors
public ChartLine() :base() {}
public ChartLine(LineData lineData) :base() {
this.lineData = lineData;
}

//Properties
public Color Color {
get { return lineColor ; }
set { lineColor = value ; }
}

public DashStyle LineStyle {
get { return lineStyle ; }
set { lineStyle = value ; }
}

public string Symbol {
get { return lineData.LineSymbol ; }
set { lineData.LineSymbol = value ; }
}

public string Title {
get { return lineData.LineTitle ; }
set { lineData.LineTitle = value ; }
}

public float[] Values {
get { return lineData.LineValues ; }
set { lineData.LineValues = value ; }
}

public int Width {
get { return lineWidth ; }
set { lineWidth = value ; }
}

//Methods
public void SetLineData(LineData lineData) {
this.lineData = lineData;
}
}

//Chart Data structure
public class ChartData {

private float yTickSize;
private float yMax;
private float yMin;
private string[] xAxisTitles ;
private ChartLineList lines = new ChartLineList();
private Color gridColor=Color.Blue;
private bool showHGridLines=true;
private bool showVGridLines=true;

//Properties
public float YTickSize {
get { return yTickSize ; }
set { yTickSize = value ; }
}

public float YMax {
get { return yMax ; }
set { yMax = value ; }
}

public float YMin {
get { return yMin ; }
set { yMin = value ; }
}

public string[] XAxisTitles {
get { return xAxisTitles ; }
set { xAxisTitles = value ; }
}

public ChartLineList Lines {
get { return lines ; }
set { lines = value ; }
}

public Color GridColor {
get { return gridColor ; }
set { gridColor = value ; }
}

public bool ShowHGridLines {
get { return showHGridLines ; }
set { showHGridLines = value ; }
}

public bool ShowVGridLines {
get { return showVGridLines ; }
set { showVGridLines = value ; }
}

//Collection of Chart Lines
public class ChartLineList : TypedCollectionBase {
public ChartLine this[int index] {
get {
return (ChartLine)(List[index]);
}
set {
List[index] = value;
}
}

public int Add(ChartLine value) {
return List.Add(value);
}

public void Insert(int index, ChartLine value) {
List.Insert(index, value);
}

public int IndexOf(ChartLine value) {
return List.IndexOf(value);
}

public bool Contains(ChartLine value) {
return List.Contains(value);
}

public void Remove(ChartLine value) {
List.Remove(value);
}

public void CopyTo(ChartLine[] array, int index) {
List.CopyTo(array, index);
}
}
}

//Charting Engine - draws a chart based on the given ChartData
public class ChartEngine {
private ChartData chartData ;
private float left;
private float right;
private float top;
private float bottom;
private float tickCount;
private float yCount;
private float hspacing;
private float vspacing;
private Graphics g;
private Rectangle r;
private Color backColor;
private Color foreColor;
private Font baseFont;
private Font legendFont;
private RectangleF legendRect;

public ChartEngine() {

}



public Bitmap DrawChart(int width, int height, ChartData chartData) {



Bitmap newBitmap = new Bitmap(width,height,PixelFormat.Format32bppARGB);

Graphics g = Graphics.FromImage(newBitmap);



Rectangle r = new Rectangle(0, 0, width, height);

Color myForeColor = Color.Black;

Color myBackColor = Color.White;

Font myFont = new Font("Arial", 10);



this.DrawChart(g, r, myBackColor, myForeColor, myFont, chartData);



return newBitmap;

}



public void DrawChart(Graphics g, Rectangle r, Color backColor,

Color foreColor, Font baseFont, ChartData chartData) {



this.chartData = chartData;

this.g = g;

this.r = r;

this.backColor = backColor;

this.foreColor = foreColor;

this.baseFont = baseFont;

this.legendFont = new Font(baseFont.FontFamily,

(baseFont.Size * 2/3), baseFont.Style | FontStyle.Bold);





g.SmoothingMode = SmoothingMode.AntiAlias;



CalculateChartDimensions();



DrawBackground();

InternalDrawChart() ;

}



private void CalculateChartDimensions() {



right = r.Width - 5;

top = 5 * baseFont.Size ;

bottom = r.Height - baseFont.Size * 2;



tickCount = chartData.YMin ;

yCount = (chartData.YMax-chartData.YMin) / chartData.YTickSize ;

hspacing = (bottom-top) / yCount;

vspacing = (right) / chartData.XAxisTitles.Length;



//Left depends on width of text - for simplicities sake assume that largest yvalue is the biggest

//Take into account the first X Axis title

float maxYTextSize = g.MeasureString(chartData.YMax.ToString(), baseFont).Width;

float firstXTitle = g.MeasureString(chartData.XAxisTitles[0], baseFont).Width;



left = (maxYTextSize > firstXTitle) ? maxYTextSize : firstXTitle ;

left = r.X + left + 5 ;



//Calculate size of legend box



float maxLegendWidth = 0 ;

float maxLegendHeight = 0 ;



//Work out size of biggest legend

foreach (ChartLine cl in chartData.Lines) {

float currentWidth = g.MeasureString(cl.Title, legendFont).Width;

float currentHeight = g.MeasureString(cl.Title, legendFont).Height;

maxLegendWidth = (maxLegendWidth > currentWidth) ? maxLegendWidth : currentWidth ;

maxLegendHeight = (maxLegendHeight > currentHeight) ? maxLegendHeight : currentHeight ;

}



legendRect = new RectangleF(r.X+2, r.Y+2, maxLegendWidth + 25 + 5, ((maxLegendHeight+2)*chartData.Lines.Count) + 3) ;

}



private void DrawBackground() {

LinearGradientBrush b = new LinearGradientBrush(r, Color.SteelBlue, backColor,LinearGradientMode.Horizontal);

g.FillRectangle(b, r);

b.Dispose();

}



private void InternalDrawChart() {



DrawGrid() ;



foreach (ChartLine cl in chartData.Lines) {

DrawLine(cl);

}



DrawLegend() ;



//Draw time on chart

string timeString = DateTime.ToString(DateTime.Now) ;

SizeF textsize = g.MeasureString(timeString,baseFont);

g.DrawString(timeString, baseFont, new SolidBrush(foreColor), r.Width - textsize.Width - 5, textsize.Height * 2 / 3) ;

}



privatevoid DrawGrid() {



Pen gridPen = new Pen(chartData.GridColor) ;



//Vertical - include tick desc's

if (chartData.ShowVGridLines) {

for (int i = 0 ; (vspacing * i) < right; i++) {

float x = left + (vspacing *i);

string desc = chartData.XAxisTitles[i];

g.DrawLine(gridPen, x,top,x,bottom +(baseFont.Size*1/3));

SizeF textsize = g.MeasureString(desc,baseFont);

g.DrawString(desc, baseFont, new SolidBrush(chartData.GridColor), x-(textsize.Width/2), bottom + (baseFont.Size*2/3)) ;

}

}



//Horizontal

if (chartData.ShowHGridLines) {

for (float i = bottom ; i > top; i-=hspacing) {

string desc = tickCount.ToString();

tickCount+=chartData.YTickSize;

g.DrawLine(gridPen, right, i, left-3, i);

SizeF textsize = g.MeasureString(desc,baseFont);

g.DrawString(desc, baseFont, new SolidBrush(chartData.GridColor), left-textsize.Width - 3, i - (textsize.Height/2)) ;

}

}

}



private void DrawLine(ChartLine chartLine) {



Pen linePen = new Pen(chartLine.Color);

linePen.StartCap = LineCap.Round;

linePen.EndCap = LineCap.Round;

linePen.Width = chartLine.Width ;

linePen.DashStyle = chartLine.LineStyle;



PointF[] Values = new PointF[chartLine.Values.Length];

float scale = hspacing / chartData.YTickSize ;



for (int i = 0 ; i < chartLine.Values.Length; i++) {

float x = left + vspacing * i;

Values[i] = new PointF(x, bottom-chartLine.Values[i]*scale);

}



g.DrawLines(linePen, Values);

}



private void DrawLegend() {



//Draw Legend Box

ControlPaint.DrawBorder(g, (Rectangle)legendRect, SystemColors.WindowFrame, ButtonBorderStyle.Solid);

LinearGradientBrush b = new LinearGradientBrush(legendRect, backColor, Color.SteelBlue, LinearGradientMode.Horizontal);

r.Inflate(-1, -1);

g.FillRectangle(b, legendRect);

b.Dispose();



float startY = 5;



foreach (ChartLine cl in chartData.Lines) {

Pen p = new Pen(cl.Color) ;

p.Width = p.Width*4;

SizeF textsize = g.MeasureString(cl.Title, legendFont);

float lineY = startY + textsize.Height / 2 ;

g.DrawLine(p, r.X + 7, lineY, r.X + 25, lineY);

g.DrawString(cl.Title, legendFont, new SolidBrush(foreColor), r.X + 30, startY);

startY += (textsize.Height+2);

}

}

}

}

2.ImageGenerator_Vb.aspx文件

<%@ Page Language="VB" ContentType="image/jpeg" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Drawing.Drawing2D" %>
<%@ Import Namespace="System.Drawing.Imaging" %>
<%@ Import Namespace="ChartGenerator" %>
<script language="VB" runat=server>
Function GetStockDetails(Symbol as String) as ChartLine
Dim myChartLine as new ChartLine
if (symbol = "msft") then
Dim StockValues() as Single = { 60, 110, 120, 180, 185, 190, 240, 290 }
myChartLine.Width = 5
myChartLine.Color = Color.White
myChartLine.LineStyle = DashStyle.Solid
myChartLine.Title = "Microsoft Corp. (MSFT)"
myChartLine.Symbol = "MSFT"
myChartLine.Values = StockValues
return myChartLine
elseif (symbol = "sun") then
Dim StockValues() as Single = { 180, 155, 125, 60, 25, 15, 10, 3 }
myChartLine.Width = 5
myChartLine.Color = Color.Red
myChartLine.LineStyle = DashStyle.Dot
myChartLine.Title = "Sun Corp. (Sun)"
myChartLine.Symbol = "Sun"
myChartLine.Values = StockValues
return myChartLine
end if
return nothing
End Function
Sub Page_Load(Sender as Object, E as EventArgs)
' Generate Chart Data For Image....
Dim XAxes() as String = { "9:00AM", "9:30AM", "10:00AM", "11:00AM", "12:00AM", "1:00PM", "1:30PM" }
Dim MyChartData as New ChartData
MyChartData.YTickSize = 20
MyChartData.YMax = 250
MyChartData.YMin = 0
MyChartData.XAxisTitles = XAxes
Dim Symbols() as String = Request.QueryString.GetValues("symbols")
if (Not Symbols Is Nothing) then
for i=0 to Symbols.Length-1
Dim stockValue as ChartLine = GetStockDetails(symbols(i).ToLower)
if (stockValue <> noting) then
myChartData.Lines.Add(stockValue)
end if
Next
end if
' Create In-Memory BitMap of JPEG
Dim MyChartEngine as New ChartEngine
Dim StockBitMap as BitMap = MyChartEngine.DrawChart(600, 400, myChartData)
' Render BitMap Stream Back To Client
StockBitMap.Save(Response.OutputStream, ImageFormat.JPEG)
End Sub
</script>

3.StockPicker.aspx文件
<script language="C#" runat=server>
void ChartBtn_Click(Object sender, EventArgs e) {
chart.ImageUrl = "ImageGenerator_Vb.aspx?";
chart.Visible = true;
foreach(ListItem item in Stocks.Items) {
if (item.Selected == true) {
chart.ImageUrl += "symbols=" + item.Value + "&";
}
}
}
</script>
<html>
<body>
<form runat=server>
<h1>Scott's Stock Picker</h1>
<asp:checkboxlist id="Stocks" runat=server>
<asp:listitem>MSFT</asp:listitem>
<asp:listitem>Sun</asp:listitem>
</asp:checkboxlist>
<asp:button text="Chart Your Selected Stocks" OnClick="ChartBtn_Click" runat=server/>
<hr>
<asp:Image id="chart" ImageUrl="" Visible=false runat=server/>
</form>
</body>
</html>

4.mk.bat文件
csc /t:library /debug+ /out:bin/chartgen.dll ChartEngine.cs /r:System.Web.dll /r:System.Winforms.dll /r:System.Drawing.dll /r:System.dll