Drawing Line Chart in ASP.NET

Steve Hall

16 Comments

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Mahsa Hassankashi14y ago
It is exactly my requirement, Thank you.
vachan chauhan15y ago
How to show Multiple Graphs on same page?
Neeraj Sharma16y ago
How to draw multiple line on same graph.
- Sandeep S16y ago
  use img tag to show graph in other browsers
Vineeta Agarwal17y ago
Hi This is the same as I needed. But I need one more thing. I have to show the tooltip of each point. How can i do that? I have Drawen the (3,45) point as string at that point but it is showen like mirror image. Because we have rotated it on 180 angle. how can i do that?
shilin pm17y ago
this code given is working and very helpful. if any one know more about this then please help me to draw column chart (bar chart) in asp.net . waiting for your replys
jas17y ago
LineChart c = new LineChart(640, 480,Page); Error 2 Argument '3': cannot convert from 'System.Web.UI.Page' to 'Page'
rakesh lad18y ago
Hi sir, As your are using Response.OutputStream to save and dispaly the image it only work on IE browser. I find it difficulty to get same result on Opera and Netscape Navigator browser. Please do the needful. Regards, Rakesh ([email protected])
Kalyan Manadapti18y ago
help me out for placing Y1 and Y2 axis for a single X Axis, Bot Y1 and Y2 values are different.
Kalyan Manadapti18y ago
I want a sample code for Windows appliaction
Jeff Cambier19y ago
Do you have the code in VB.Net for this line graph for ASP.Net? Thanks. [email protected]
Hari Singh19y ago
protected void Page_Load(object sender, EventArgs e) { LineChart lc= new LineChart(640, 480, Page); lc.Title = "My Line Chart"; lc.Xorigin = 0; lc.ScaleX = 500; lc.Xdivs = 5; lc.Yorigin = 0; lc.ScaleY = 1000; lc.Ydivs = 5; lc.AddValue(50, 50); lc.AddValue(100, 100); lc.AddValue(200, 150); lc.AddValue(450, 450); Draw(); } 'LineChart1.LineChart(int, int, System.Web.UI.Page)' is a 'method' but is used like a 'type'
Hari Singh19y ago
'LineChart1.LineChart(int, int, .Web.UI.Page)' is a 'method' but is used like a 'type'
Nguyen Xuan Quang19y ago
chartValues.Add(myPoint) Error : Name 'ChartValues' doesn't exist in a present context.
- Amit Dahiya19y ago
  Use System.Collections and System.Collections.Generic namespace to resolve this problem.....
- Steve Hall19y ago
  The listvalue is named chartValues, not ChartValues.

Save the following code as an .ASPX web page on your .NET web server to try this sample using GDI+ encapsulated in a class to display a primitive line chart. The class features an arraylist to hold a dynamic number of chart points and utilizes transforms to simplify the plotting of worldview data points. Enhancements would add color options, multiple lines, other chart types, and printing.

<%@ Page Language="C#" %>

<%@ Import Namespace="System" %>

<%@ Import Namespace="System.Drawing" %>

<%@ Import Namespace="System.Drawing.Drawing2D" %>

<%@ Import Namespace="System.Drawing.Imaging" %>

class LineChart

{

//Sample ASPX C# LineChart Class

public Bitmap b;

public string Title="Default Title";

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;

}

//initialize

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.Black,1);

Brush blackBrush = new SolidBrush(Color.Black);

Font axesFont = new Font("arial",10);

//first establish working area

p.Response.ContentType="image/jpeg";

g.FillRectangle(new

SolidBrush(Color.LightYellow),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);

//must draw all text items before doing the rotate below

g.DrawString(Title, new Font("arial",14), blackBrush, Width/3, 10);

//draw X axis labels

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);

}

//draw Y axis labels

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);

}

//transform drawing coords to lower-left (0,0)

g.RotateTransform(180);

g.TranslateTransform(0,-Height);

g.TranslateTransform(-ChartInset,ChartInset);

g.ScaleTransform(-1, 1);

//draw chart data

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;

}

//finally send graphics to browser

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="My Line Chart";

c.Xorigin=0; c.ScaleX=500; c.Xdivs=5;

c.Yorigin=0; c.ScaleY=1000; c.Ydivs=5;

c.AddValue(50,50);

c.AddValue(100,100);

c.AddValue(200,150);

c.AddValue(450,450);

c.Draw();

}

</script>