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Posted 20 Sep 2007


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Open Source QRCode Library

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20 Sep 2007CPOL1 min read
How to use QRCode library to encode and decode QRCode
Screenshot - qrcode_app_decode.jpg


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


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

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!");
          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;


  • 20th September, 2007: Initial post


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


About the Author

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.

Comments and Discussions

AnswerRe: 对中文的支持还是不够! Pin
xoyozo23-Mar-12 4:49
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QuestionMemoryStream memoryStream = new MemoryStream(Resources.GetResource(fileName)); Pin
S.Sams22-Nov-11 21:46
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AnswerRe: MemoryStream memoryStream = new MemoryStream(Resources.GetResource(fileName)); Pin
tomeekgd11-Mar-12 12:29
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QuestionChanging the QR foreground colour Pin
rambasnet3210-Nov-11 6:03
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SuggestionPerformance Pin
Havardo12-Oct-11 23:35
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GeneralRe: Performance Pin
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BugBug in BCH15_5.cs calcSyndrome(...) ? Pin
SergeyKS11-Oct-11 23:23
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QuestionResources.GetResource? Pin
ak165-Oct-11 5:12
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AnswerRe: Resources.GetResource? Pin
ak165-Oct-11 5:40
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GeneralRe: Resources.GetResource? Pin
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GeneralRe: Resources.GetResource? Pin
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GeneralRe: Resources.GetResource? Pin
S.Sams22-Nov-11 21:48
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QuestionGreat help Pin
maoflo3-Oct-11 10:42
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Questionwhat's the use of resources file "qrv#_#.dat","qrvfr.dat","rsc.dat"? Pin
tingispig28-Sep-11 23:23
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AnswerRe: what's the use of resources file "qrv#_#.dat","qrvfr.dat","rsc.dat"? Pin
wvd_vegt31-Jan-12 0:45
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QuestionQR Code Not Working Pin
Gigi1001218-Sep-11 3:38
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Questionsin cos for use in calc for skew???? Pin
boblogan6-Sep-11 21:54
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QuestionLicensing Pin
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QuestionTo many errors and wanring using VS 2010 Pin
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BugArrayOutOfRangeException because of (sbyte i = 1; i < 128; i++) Pin
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GeneralRe: ArrayOutOfRangeException because of (sbyte i = 1; i < 128; i++) Pin
tristan1433-Aug-11 22:10
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QuestionQR code for windows phone Pin
saini4826-Jul-11 14:52
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QuestionBeware - generated image is not QRCode compliant. Pin
EricT.21-Jun-11 7:49
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AnswerRe: Beware - generated image is not QRCode compliant. Pin
Manadar25-Jul-11 4:17
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QuestionRe: Beware - generated image is not QRCode compliant. Pin
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