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Posted 31 Mar 2003


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C# Barcode Generator WebService

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31 Mar 2003BSD3 min read
Create a code39 barcode using a webservice in C#

Sample Image - barcodegen.jpg


Some days ago, I was asked to find a solution to create a barcode to be printed on documents produced by a web application. After trying to find some components that produced barcodes, I soon realized that their price was very high when dealing with an unlimited number of clients licences. I needed an alphanumeric barcode representation and the preferred barcode representation was Code39.

In order to expose this service to the maximum of clients while delivering a standardized solution, I thought of writing a web service that would generate the barcode dynamically and return it streamlined as an image.

This article describes the solution that I’ve implemented.

The Barcode Generation

Instead of writing a code39 barcode generator that mimics the algorithm for that barcode representation, my idea was to use one of the freely available barcode fonts to produce the barcode (

So my approach was simple:

  1. Load the Barcode Font
  2. Create an image object
  3. Draw a string into that image using a code39 barcode font
  4. Return that image serialized.

Using the Code39 Font...

The way to use a font in windows is simple, all you have to do is install it (by copying it to the c:\WINDOWS\Fonts - under XP) and just use it.

Unfortunately, the ASP.NET graphic context does not allow you to use any font  (free3of9.ttf for example) because .NET GDI only uses/enumerates OpenType fonts. So what you have to do is create a temporary font object.

This method is very straighforward, as you can see in the code sample below:

// Create a private font collection
objectPrivateFontCollection pfc=new PrivateFontCollection();

// Load in the temporary barcode font

// Select the font family to use
FontFamily family=new FontFamily("Free 3 of 9",pfc);

// Create the font object with size 30
Font c39Font=new Font(family,30);

With this easy way, you get a font object mapped to the barcode font so that you can create the barcode.

Creating the Barcode Image Container

The image creation is very simple. .NET classes allow you to generate images on the fly. So, in order to create a image large enough to accommodate the barcode, first you need to determine the size that will be occupied by the code string drawing, using the barcode font.

You can do it using the MeasureString method:

// Create a temporary bitmap...
Bitmap tmpBitmap = new Bitmap(1,1,PixelFormat.Format32bppArgb);
objGraphics = Graphics.FromImage(tmpBitmap);
// measure the barcode size...
SizeF barCodeSize=objGraphics.MeasureString(barCodeString,c39Font);

The returned type barCodeSize has the width, and the height that will be occupied by the code string drawing.

Draw the Barcode

So now we need to draw the barcode. We will use the code39 barcode font object instantiated earlier.

Assuming the the barcode variable holds the barcode string, the required code is:

// Draw the barcode
objGraphics.DrawString(barCode, Code39Font, new solidBrush(Color.Black),0,0);

Please note that usualy the code39 barcodes are represented concatenating  the char (*) at the beginning and end of the barcode string…meaning that code 123456 has to be written as *123456*. But I will leave that to your experience.

Serialize/Deserialize the Image

In order to return the image from the web service method, you now have to serialize the image, meaning that your web method has to return an array of bytes.

This way, you have to create a stream from the bitmap image, and return it as an array of bytes. Once again, the .NET framework makes it easy for us do perform that task:

// Create stream....
MemoryStream ms = new MemoryStream();

// save the image to the stream
objBitmap.Save(ms ,ImageFormat.Png);

//return an array of bytes....
return ms.GetBuffer();

On the other end (the client side) when you are consuming the web service, you need to be able to deserialize the array of bytes back to the image:

Byte[] imgBarcode;

// Call the webservice to create the barcode...

// Create a stream....
MemoryStream memStream = new MemoryStream(imgBarcode);

// Recreate the image from the stream<BR>Bitmap bmp=new Bitmap(memStream);

A final note about the sample code attached…

After creating the barcode web app that will be your webservice, you need to configure the web.config file in order to specify where your barcode font is located. Search for the following section and make your changes accordingly.

   <add key="BarCodeFontFile" value="c:\temp\font\FREE3OF9.TTF" />
   <add key="BarCodeFontFamily" value="Free 3 of 9" />        

And that’s all folks. Hope you’ve enjoyed it.

Best regards,
Rui Miguel Barbosa


This article, along with any associated source code and files, is licensed under The BSD License


About the Author

Rui Miguel Barbosa
Web Developer
Portugal Portugal
No Biography provided

Comments and Discussions

QuestionGood job Pin
PatrickBaudry9-Nov-16 2:38
MemberPatrickBaudry9-Nov-16 2:38 
GeneralMy vote of 5 Pin
rosdi13-Aug-15 7:32
Memberrosdi13-Aug-15 7:32 
GeneralMy vote of 5 Pin
Man629-Jul-13 22:59
MemberMan629-Jul-13 22:59 
Questionqrcode Pin
Member 917112825-Nov-12 21:35
MemberMember 917112825-Nov-12 21:35 
AnswerUseful information Pin
sybil_25-Sep-12 17:30
Membersybil_25-Sep-12 17:30 
QuestionUnable to scan barcode which was generated by using 28 digit string Pin
KiranRViradiya25-Apr-12 23:52
MemberKiranRViradiya25-Apr-12 23:52 
AnswerRe: Unable to scan barcode which was generated by using 28 digit string Pin
sybil_25-Sep-12 17:32
Membersybil_25-Sep-12 17:32 
AnswerMessage Closed Pin
4-Jan-13 16:19
MemberSusanna Moore4-Jan-13 16:19 
GeneralGreat article Pin
Jason from Florida25-Jan-12 1:12
MemberJason from Florida25-Jan-12 1:12 
GeneralMy vote of 5 Pin
Teddy Segoro1-Dec-11 19:53
MemberTeddy Segoro1-Dec-11 19:53 
Questionhow use this generator in web applicathion Pin
saidfathi5-Nov-11 2:43
Membersaidfathi5-Nov-11 2:43 
AnswerMessage Closed Pin
20-Feb-12 16:15
Memberblueskysinger20-Feb-12 16:15 
Questionhow can i read and write barcode through 2005 Pin
Jalesh Singh25-Aug-11 20:23
MemberJalesh Singh25-Aug-11 20:23 
AnswerMessage Closed Pin
24-Nov-11 19:55
MemberIvy Shirley24-Nov-11 19:55 
AnswerMessage Closed Pin
8-Jan-12 3:28
MemberWebMaster8-Jan-12 3:28 
Questionhow to read this generated bar code Pin
dprapireddy30-Jun-11 1:55
Memberdprapireddy30-Jun-11 1:55 
GeneralWorking for me Pin
amit k saini3-Jun-11 1:37
Memberamit k saini3-Jun-11 1:37 
GeneralMy vote of 5 Pin
johannesnestler3-Nov-10 5:10
Memberjohannesnestler3-Nov-10 5:10 
GeneralBarcode 2 of 5 Pin 4:19 4:19 
QuestionString(Alphabatical) value unable to convert to the barcode format Pin
Rajiredy17-May-10 22:54
MemberRajiredy17-May-10 22:54 
GeneralDude you rock :) Pin
Raphael Shekwolo8-Apr-10 1:39
MemberRaphael Shekwolo8-Apr-10 1:39 
GeneralWant ot read barcode image form Tiff File Pin
PankajRai.Net18-Sep-09 19:30
MemberPankajRai.Net18-Sep-09 19:30 
GeneralScanner couldn't scan the printed barcodes.., (scanner says it supports code39) Pin
saurabhnijhawan198716-Jun-09 20:25
Membersaurabhnijhawan198716-Jun-09 20:25 
Generalgetting an error while running Pin
kutti krishnan kodoth12-Jun-09 19:06
Memberkutti krishnan kodoth12-Jun-09 19:06 
GeneralScanner Couldn't read Pin
murtaza dhari9-Feb-09 23:52
Membermurtaza dhari9-Feb-09 23:52 

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