ASP.NET实现数据图表1

＜%@ Import Namespace = "System" %＞
＜%@ Import Namespace = "System.Drawing" %＞
＜%@ Import Namespace = "System.Drawing.Drawing2D" %＞
＜%@ Import Namespace = "System.Drawing.Imaging" %＞ 
＜script language = "C#" runat = "server" ＞

class LineChart
{
public Bitmap b ;
public string Title = "在ASP.NET中实现数据图表" ;
public ArrayList chartValues = new ArrayList ( ) ;
public float Xorigin = 0 , Yorigin = 0 ;
public float ScaleX , ScaleY ;
public float Xdivs = 2 , Ydivs = 2 ;

private int Width , Height ;
private Graphics g ;
private Page p ;

struct datapoint {
public float x ;
public float y ;
public bool valid ;
}

//初始化
public LineChart ( int myWidth , int myHeight , Page myPage ) {
Width = myWidth ; Height = myHeight ;
ScaleX = myWidth ; ScaleY = myHeight ;
b = new Bitmap ( myWidth , myHeight ) ;
g = Graphics . FromImage ( b ) ;
p = myPage ;
}

public void AddValue ( int x , int y ) {
datapoint myPoint ;
myPoint . x = x ;
myPoint . y = y ;
myPoint . valid = true ;
chartValues . Add ( myPoint ) ;
}

public void Draw ( ) {
int i ;
float x , y , x0 , y0 ;
string myLabel ;
Pen blackPen = new Pen ( Color . Blue , 2 ) ;
Brush blackBrush = new SolidBrush ( Color . Black ) ;
Font axesFont = new Font ( "arial" , 10 ) ;

//首先要创建图片的大小
p . Response . ContentType = "image/jpeg" ;
g . FillRectangle ( new SolidBrush ( Color . LightGreen ) , 0 , 0 , Width , Height ) ;
int ChartInset = 50 ;
int ChartWidth = Width - ( 2 * ChartInset ) ;
int ChartHeight = Height - ( 2 * ChartInset ) ;
g . DrawRectangle ( new Pen ( Color . Black , 1 ) , ChartInset , ChartInset , ChartWidth , ChartHeight ) ;
//写出图片上面的图片内容文字
g . DrawString ( Title , new Font ( "arial" , 14 ) , blackBrush , Width / 3 , 10 ) ;
//沿X坐标写入X标签
for ( i = 0 ; i ＜= Xdivs ; i++ ) {
x = ChartInset + ( i * ChartWidth ) / Xdivs ;
y = ChartHeight + ChartInset ;
myLabel = ( Xorigin + ( ScaleX * i / Xdivs ) ) . ToString ( ) ;
g . DrawString ( myLabel , axesFont , blackBrush , x - 4 , y + 10 ) ;
g . DrawLine ( blackPen , x , y + 2 , x , y - 2 ) ;
}
//沿Y坐标写入Y标签
for ( i = 0 ; i ＜= Ydivs ; i++ )
{
x = ChartInset ;
y = ChartHeight + ChartInset - ( i * ChartHeight / Ydivs ) ;
myLabel = ( Yorigin + ( ScaleY * i / Ydivs ) ) . ToString ( ) ;
g . DrawString ( myLabel , axesFont , blackBrush , 5 , y - 6 ) ;
g . DrawLine ( blackPen , x + 2 , y , x - 2 , y ) ;
}
g . RotateTransform ( 180 ) ;
g . TranslateTransform ( 0 , - Height ) ;
g . TranslateTransform ( - ChartInset , ChartInset ) ;
g . ScaleTransform ( - 1 , 1 ) ;

//画出图表中的数据
datapoint prevPoint = new datapoint ( ) ;
prevPoint . valid = false ;
foreach ( datapoint myPoint in chartValues ) {
if ( prevPoint . valid == true ) {
x0 = ChartWidth * ( prevPoint . x - Xorigin ) / ScaleX ;
y0 = ChartHeight * ( prevPoint . y - Yorigin ) / ScaleY ;
x = ChartWidth * ( myPoint . x - Xorigin ) / ScaleX ;
y = ChartHeight * ( myPoint . y - Yorigin ) / ScaleY ;
g . DrawLine ( blackPen , x0 , y0 , x , y ) ;
g . FillEllipse ( blackBrush , x0 - 2 , y0 - 2 , 4 , 4 ) ;
g . FillEllipse ( blackBrush , x - 2 , y - 2 , 4 , 4 ) ;
}
prevPoint = myPoint ;
}

//最后以图片形式来浏览
b . Save ( p . Response . OutputStream , ImageFormat . Jpeg ) ;
}

~LineChart ( ) {
g . Dispose ( ) ;
b . Dispose ( ) ;
}
}
void Page_Load ( Object sender , EventArgs e ) 
{
LineChart c = new LineChart ( 640 , 480 , Page ) ;
c . Title = " 在ASP.NET中实现数据图表" ;
c . Xorigin = 0 ; c . ScaleX = 500 ; c . Xdivs = 5 ;
c . Yorigin = 0 ; c . ScaleY = 1000 ; c . Ydivs = 5 ;
c . AddValue ( 0 , 150 ) ;
c . AddValue ( 50 , 50 ) ;
c . AddValue ( 100 , 700 ) ;
c . AddValue ( 200 , 150 ) ;
c . AddValue ( 300 , 450 ) ;
c . AddValue ( 400 , 75 ) ;
c . AddValue ( 450 , 450 ) ;
c . AddValue ( 500 , 250 ) ;
c . Draw ( ) ;
}
＜/script ＞