Project UI (1) QR code

Preface

Series of articles:[Portal]

I have been idle for weeks. No, no. Blog, I don't know when you will change it. I will not forget you. Well, I will also update it on the OS and csdn. Every day, no matter how useful or useless.

 

Body

The main body of this article is to start with a project, with clear requirements in the project.

Scan the QR code to implement the sign-in function.

Naturally, it is linked to the app. It's okay. Let's take a step.

QR code

A QR code (QR code), also known as a two-dimensional barcode, is a black-and-white image distributed on a plane (two-dimensional direction) based on a specific geometric pattern, it is a key to all information data.

　　

Zxing

ZXing is an open-source code library that uses multiple formats of 1D/2D bar code image processing implemented in Java. It contains ports connected to other languages. Zxing can scan and decode the barcode using the built-in camera of the mobile phone. Code encoding and decoding implemented by this project

You can understand

Https://github.com/zxing/zxing/wiki/Getting-Started-Developing

QR code generation

/*** Generate a QR code image ** @ param content * @ param width * @ param height * @ param imgPath stores the image path */

Package sedion. jeffli. wmuui. util. zxing; import java. io. file; import java. util. hashtable; import com. google. zxing. barcodeFormat; import com. google. zxing. encodeHintType; import com. google. zxing. multiFormatWriter; import com. google. zxing. client. j2se. matrixToImageWriter; import com. google. zxing. common. bitMatrix; import com. google. zxing. qrcode. decoder. errorCorrectionLevel;/*** @ author Jeff Lee */public class ZxingEncoderHelper {/*** generates a QR code image * @ param content * @ param width * @ param height * @ param imgPath stores the image path */public void encode (String content, int width, int height, String imgPath) {Hashtable <EncodeHintType, Object> hts = new Hashtable <EncodeHintType, Object> (); hts. put (EncodeHintType. ERROR_CORRECTION, ErrorCorrectionLevel. l); // Error Correction level (hts. put (EncodeHintType. CHARACTER_SET, "UTF-8 ");// Specify encoding format as UTF-8 try {BitMatrix bitMatrix = new MultiFormatWriter (). encode (content, // encoding content, encoding type (specified here as a QR code), BarcodeFormat. QR_CODE, width, height, hts); // specifies the image width and height. Set the parameter MatrixToImageWriter. writeToFile (bitMatrix, "png", new File (imgPath); // generated QR code image} catch (Exception e) {e. printStackTrace () ;}} public static void main (String [] args) {String imgPath = "d:/33.png"; String contents =" Hello! My blog: http://www.cnblogs.com/Alandre/ "; int width = 300, height = 300; ZxingEncoderHelper handler = new ZxingEncoderHelper (); handler. encode (contents, width, height, imgPath );}}

# BitMatrix parameters: encoding content, encoding type, generating image width, generating image height, and setting parameters

# MatrixToImageWriter

 

You will find this image

　　

　

QR code decoding

　　

/*** Decode * @ param imgPath: QR code image path * @ return */

Package sedion. jeffli. wmuui. util. zxing; import java. awt. image. bufferedImage; import java. io. file; import java. util. hashtable; import javax. imageio. imageIO; import com. google. zxing. binaryBitmap; import com. google. zxing. decodeHintType; import com. google. zxing. luminanceSource; import com. google. zxing. multiFormatReader; import com. google. zxing. result; import com. google. zxing. client. j2se. bufferedImageLuminanceSo Urce; import com. google. zxing. common. hybridBinarizer;/*** @ author Jeff Lee */public class ZxingDecoderHandler {/*** decodes * @ param imgPath QR code image path * @ return */public String decode (String imgPath) {BufferedImage image = null; Result result = null; try {image = ImageIO. read (new File (imgPath); if (image = null) {System. out. println ("the file does not exist! "); // An exception should be thrown} LuminanceSource source = new BufferedImageLuminanceSource (image); BinaryBitmap bitmap = new BinaryBitmap (new HybridBinarizer (source); Hashtable <DecodeHintType, object> hints = new Hashtable <DecodeHintType, Object> (); hints. put (DecodeHintType. CHARACTER_SET, "UTF-8"); result = new MultiFormatReader (). decode (bitmap, hints); return result. getText ();} catch (Exception e) {e. printStackTrace ();} return null;} public static void main (String [] args) {String imgPath = "d:/33.png"; ZxingDecoderHandler handler = new ZxingDecoderHandler (); string content = handler. decode (imgPath); System. out. println ("content:"); System. out. println (content );}}

 

# Opposite to generation

　　　

Summary

　QR code generation

QR code decoding

 

Thanks and Resource Sharing

　　　　

One step on the road, I hope everyone will join me.

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Knowledge Source: https://github.com/zxing/zxing/wiki/Getting-Started-Developing