Click here to Skip to main content
15,867,308 members
Articles / Programming Languages / C#
Article

Open Source QRCode Library

Rate me:
Please Sign up or sign in to vote.
4.92/5 (147 votes)
20 Sep 2007CPOL1 min read 5.9M   192.2K   420   334
How to use QRCode library to encode and decode QRCode
Screenshot - qrcode_app_decode.jpg

Introduction

In this article, I will briefly describe the functionalities of the QRCode library.

Background

QRCode library is a .NET component that can be used to encode and decode QRCode. QRCode is a 2 dimensional bar code that originated in Japan. Nowadays, it is widely used in a wide range of industries, e.g. for vehicle parts tracking and inventory management.

QR stands for "Quick Response". It was created by the Japanese corporation Denso-Wave in 1994 and is aimed at decoding contents at high speed. Nowadays, QR Code is used in mobile phones to ease data entry.

QRCode can also be printed on a business card or shown on any display, which can then be captured by the mobile phone provided the mobile phone has the software to read QRCode.

QRCode library provides functions to:

  1. Encode content into a QR Code image which can be saved in JPEG, GIF, PNG, or Bitmap formats
  2. Decode a QR Code image

Using the Code

The library can be used in any .NET 2.0 Windows Application, ASP.NET Web application or Windows Mobile device application.

Some sample screenshots are displayed below:

Screenshot - qrcode_app_encode.jpg

Screenshot - qrcode_mobile_encode.jpg

C#
QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
          String encoding = cboEncoding.Text ;
          if (encoding == "Byte") {
              qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
          } else if (encoding == "AlphaNumeric") {
              qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.ALPHA_NUMERIC;
          } else if (encoding == "Numeric") {
              qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.NUMERIC;
          }
          try {
              int scale = Convert.ToInt16(txtSize.Text);
              qrCodeEncoder.QRCodeScale = scale;
          } catch (Exception ex) {
              MessageBox.Show("Invalid size!");
              return;
          }
          try {
              int version = Convert.ToInt16(cboVersion.Text) ;
              qrCodeEncoder.QRCodeVersion = version;
          } catch (Exception ex) {
              MessageBox.Show("Invalid version !");
          }

          string errorCorrect = cboCorrectionLevel.Text;
          if (errorCorrect == "L")
              qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.L;
          else if (errorCorrect == "M")
              qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
          else if (errorCorrect == "Q")
              qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.Q;
          else if (errorCorrect == "H")
              qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.H;

          Image image;
          String data = txtEncodeData.Text;
          image = qrCodeEncoder.Encode(data);
          picEncode.Image = image;

History

  • 20th September, 2007: Initial post

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior)
Malaysia Malaysia
A programmer for a long time, and still learning everyday.

A supporter for open source solutions, and have written quite a few open source software both in .NET and Java.

https://mengwangk.github.io/

Comments and Discussions

 
GeneralRe: IndexOutOfRangeException in rsTemp Pin
jonataspc30-Jul-09 7:17
jonataspc30-Jul-09 7:17 
AnswerRe: IndexOutOfRangeException in rsTemp [modified] Pin
JackyFan22-Sep-09 17:55
JackyFan22-Sep-09 17:55 
QuestionIs this free? Pin
Carl00722-Mar-09 20:16
Carl00722-Mar-09 20:16 
AnswerRe: Is this free? Pin
aprilkacau25-Mar-09 18:57
aprilkacau25-Mar-09 18:57 
GeneralRe: Is this free? Pin
Carl00726-Mar-09 15:20
Carl00726-Mar-09 15:20 
GeneralError on VisualStudio 2008 Pin
Z@clarco19-Mar-09 4:33
Z@clarco19-Mar-09 4:33 
GeneralRe: Error on VisualStudio 2008 Pin
aprilkacau25-Mar-09 18:55
aprilkacau25-Mar-09 18:55 
GeneralResources.GetResource Pin
aprilkacau16-Mar-09 6:15
aprilkacau16-Mar-09 6:15 
Error : 'ThoughtWorks.QRCode.Properties.Resources' does not contain a definition for 'GetResource'
File : "E:\projects\QRCode\QRCodeLib\QRCodeEncoder.cs"
Line : 452
Column : 72
Project : QRCodeLib

The class doesn't have GetResources method. And I don't know what it do, so I can't just add it with some mumbling random code ... :P.

It seems that I'm the only one that got this problem, maybe I've downloaded the incorrect file ? And so, I tried download it, and it's still the same.
GeneralRe: Resources.GetResource Pin
gdhaifeng25-Mar-09 5:29
gdhaifeng25-Mar-09 5:29 
GeneralRe: Resources.GetResource Pin
gdhaifeng25-Mar-09 5:43
gdhaifeng25-Mar-09 5:43 
GeneralRe: Resources.GetResource Pin
aprilkacau25-Mar-09 18:50
aprilkacau25-Mar-09 18:50 
GeneralRe: Resources.GetResource Pin
Andrea_8622-Dec-09 8:06
Andrea_8622-Dec-09 8:06 
AnswerRe: Resources.GetResource Pin
iChov6-Jan-10 19:05
iChov6-Jan-10 19:05 
GeneralRe: Resources.GetResource Pin
VTRUNG45628-Dec-11 19:46
VTRUNG45628-Dec-11 19:46 
Generallearner Pin
sultankeshwar26-Jan-09 23:41
sultankeshwar26-Jan-09 23:41 
QuestionMobile Built-in Camera Pin
Abdelrazag3-Jan-09 20:52
Abdelrazag3-Jan-09 20:52 
Generalasp.net avaible Pin
blogscreen18-Dec-08 0:38
blogscreen18-Dec-08 0:38 
Generaltoo slow on the ARM PXA270(WindowsMobile) Pin
Yohei Murakami10-Oct-08 20:50
Yohei Murakami10-Oct-08 20:50 
GeneralRe: too slow on the ARM PXA270(WindowsMobile) Pin
Yohei Murakami10-Oct-08 21:09
Yohei Murakami10-Oct-08 21:09 
GeneralRe: too slow on the ARM PXA270(WindowsMobile) Pin
fubeidong22-Oct-08 21:06
fubeidong22-Oct-08 21:06 
GeneralRe: too slow on the ARM PXA270(WindowsMobile) Pin
dianzisun12-Nov-08 15:27
dianzisun12-Nov-08 15:27 
GeneralRe: too slow on the ARM PXA270(WindowsMobile) Pin
dianzisun12-Nov-08 15:41
dianzisun12-Nov-08 15:41 
QuestionQR Code Mobile Phone Encoding Issue Pin
Saurabh Sondhi7-Oct-08 9:09
Saurabh Sondhi7-Oct-08 9:09 
Questionhave you done another job? decode the QRcode in a real photo taken by a camera? Pin
hillgong5-Sep-08 2:23
hillgong5-Sep-08 2:23 
General"Give up decoding" Pin
skjamesbond18-Aug-08 2:15
skjamesbond18-Aug-08 2:15 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.