Counter.aspx
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Drawing.Imaging" %>
<%@ Import Namespace="System.Drawing.Drawing2d" %>
<%
' ***** MANAGE COUNTER VALUE CREATION, RESTORATION, AND SAVING *****
' Get the counter ID (unique to each counter in the site)
dim counterid as String = request("id")
' Get current counter value
dim value as Integer = cint(Application("Counter_" & counterid))
if Session("CounterTemp_" & counterid) is Nothing then
' If the text file exists load the saved value
' Always loading it from the file rather than just using the application
variable allows for manual modification of counter values while the application
is running (by editing the text file). To stop it from being able to be modified
just uncomment the following 'if..then' and the 'end if'. This will give
a slight performance boost to the counter incrementing as it will stop a file
operation. Yes, I'm an optimization freak! :)
'if value = 0 then
if File.Exists(server.mappath(counterid & ".txt"))
then
dim sr as StreamReader = File.OpenText(server.mappath(counterid & ".txt"))
value = cint(sr.ReadLine().ToString())
sr.Close
end if
'end if
' Increment counter
value += 1
' Save counter to an application var (the locks are there to make
sure noone else changes it at the same time)
Application.Lock()
Application("Counter_" & counterid) = value.ToString()
Application.UnLock()
' Save counter to a text file
dim fs as FileStream = new FileStream(server.mappath(counterid & ".txt"),
FileMode.Create, FileAccess.Write)
dim sw as StreamWriter = new StreamWriter(fs)
sw.WriteLine(Convert.ToString(value))
sw.Close
fs.Close
' Set a session variable so this counter doesn't fire again in the
current session
Session.Add(("CounterTemp_" & counterid), "True")
end if
' ***** CREATE OUTPUT GRAPHIC FOR THE COUNTER *****
' Load digits graphic (must be in 0 through 9 format in graphic w/ all digits
of set width)
dim i as System.Drawing.Image = System.Drawing.Image.FromFile(server.mappath(request("src")))
' Get digit dynamics from the graphic
dim dgwidth as Integer = i.width/10
dim dgheight as Integer = i.height
' Get number of digits to display in the output graphic
dim digits as Integer = cint(request("digits"))
' Create output object
dim imgOutput as New Bitmap(dgwidth*digits, dgheight, pixelformat.format24bpprgb)
dim g as graphics = graphics.fromimage(imgOutput)
dim j as Integer, dg as Integer
for j = 0 to (digits-1)
' Extract digit from value
dg = fix(value / (10^(digits - j - 1))) - fix(value / (10^(digits
- j)))*10
' Add digit to the output graphic
g.drawimage(i, New rectangle(j*dgwidth, 0, dgwidth, dgheight), New
rectangle(dg*dgwidth, 0, dgwidth, dgheight), GraphicsUnit.Pixel)
next j
' Set the content type and return output image
response.contenttype="image/jpeg"
imgOutput.save(response.outputstream, imageformat.jpeg)
' Clean up
g.dispose()
imgOutput.dispose()
%>
Step 1: To use this page, simply do
<img src="counter/counter.aspx?src=digits.gif&digits=5&id=countername">
where
src - Name of the graphic counter file digits - How many no of digits you want (with leading zeros) id - Counter ID (creates a text file, if the id
is not there)
Step 2: Make sure that, the IIS User login account have
write access permission to the directory to which the couter files are stored.
e.g. in our case 'Counter'
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