Generation and resolution of QR codes

This example uses text to generate the corresponding QR code image and parse the content of the QR code image. The Code is as follows:

MainActivity:

Package com. home. testqrcode; import java. util. hashMap; import java. util. hashtable; import java. util. map; import android. app. activity; import android. graphics. bitmap; import android. graphics. drawable. bitmapDrawable; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. widget. button; import android. widget. editText; import android. widget. imageView; import and Roid. widget. textView; import android. widget. toast; import com. google. zxing. barcodeFormat; import com. google. zxing. binaryBitmap; import com. google. zxing. decodeHintType; import com. google. zxing. encodeHintType; import com. google. zxing. result; import com. google. zxing. writerException; import com. google. zxing. client. androidtest. RGBLuminanceSource; import com. google. zxing. common. bitMatrix; import com. google. zxing. Common. hybridBinarizer; import com. google. zxing. qrcode. QRCodeReader; import com. google. zxing. qrcode. QRCodeWriter; public class MainActivity extends Activity implements OnClickListener {private Button generateBtn; private Button decodeQRCodeBtn; private ImageView imageView; private TextView textView; private EditText contentText; private static int QR_WIDTH = 400; private static int QR_HEIGHT = 400; @ Overrid Eprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. main); initWidget ();} private void initWidget () {generateBtn = (Button) findViewById (R. id. main_btn_generateQRCode); generateBtn. setOnClickListener (this); decodeQRCodeBtn = (Button) findViewById (R. id. main_btn_decodeQRCode); decodeQRCodeBtn. setOnClickListener (this); imageView = (ImageView) findV IewById (R. id. main_iv); textView = (TextView) findViewById (R. id. main_ TV); contentText = (EditText) findViewById (R. id. main_et) ;}@ Overridepublic void onClick (View v) {if (v = generateBtn) {String text = contentText. getText (). toString (); if ("". equals (text) | null = text) {Toast. makeText (this, "Enter the content", Toast. LENGTH_SHORT ). show (); return;} Bitmap bitmap = createBitmap (text); if (bitmap! = Null) {imageView. setImageBitmap (bitmap) ;}} else if (v = decodeQRCodeBtn) {String content = readImage (imageView); textView. setText (content) ;}}/*** generate a QR code image ** @ return */private Bitmap createBitmap (String text) {Bitmap bitmap = null; try {Hashtable
 
  
Hints = new Hashtable
  
   
(); Hints. put (EncodeHintType. CHARACTER_SET, "UTF-8"); BitMatrix bitMatrix = new QRCodeWriter (). encode (text, BarcodeFormat. QR_CODE, QR_WIDTH, QR_HEIGHT, hints); // QRCodeWriter writer = new QRCodeWriter (); // convert the input text into a QR code // BitMatrix bitMatrix = writer. encode (text, BarcodeFormat. QR_CODE, // QR_WIDTH, QR_HEIGHT); int [] pixels = new int [QR_WIDTH * QR_HEIGHT]; for (int y = 0; y <QR_HEIGHT; y ++) {for (int x = 0; x <QR_WIDTH; x ++) {if (bitMatrix. get (x, y) {pixels [y * QR_WIDTH + x] = 0xff000000;} else {pixels [y * QR_WIDTH + x] = 0 xffffffff ;}}} bitmap = Bitmap. createBitmap (QR_WIDTH, QR_HEIGHT, Bitmap. config. ARGB_8888); bitmap. setPixels (pixels, 0, QR_WIDTH, 0, 0, QR_WIDTH, QR_HEIGHT);} catch (WriterException e) {e. printStackTrace ();} return bitmap;}/*** parse the QR image content ** @ param imageView * @ return */private String readImage (ImageView imageView) {String content = null; map
   
    
Hints = new HashMap
    
     
(); Hints. put (DecodeHintType. CHARACTER_SET, "UTF-8"); // obtain the image to be parsed Bitmap bitmap = (BitmapDrawable) imageView. getDrawable ()). getBitmap (); RGBLuminanceSource source = new RGBLuminanceSource (bitmap); BinaryBitmap bitmap1 = new BinaryBitmap (new region (source); QRCodeReader reader = new QRCodeReader (); try {Result = reader. decode (bitmap1, hints); // obtain the parsed text content = result. getText ();} catch (Exception e) {e. printStackTrace () ;}return content ;}}
    
   
  
 

RGBLuminanceSource:

package com.google.zxing.client.androidtest;import com.google.zxing.LuminanceSource;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import java.io.FileNotFoundException;/** * This class is used to help decode images from files which arrive as RGB data * from Android bitmaps. It does not support cropping or rotation. *  * @author dswitkin@google.com (Daniel Switkin) */public final class RGBLuminanceSource extends LuminanceSource {private final byte[] luminances;public RGBLuminanceSource(String path) throws FileNotFoundException {this(loadBitmap(path));}public RGBLuminanceSource(Bitmap bitmap) {super(bitmap.getWidth(), bitmap.getHeight());int width = bitmap.getWidth();int height = bitmap.getHeight();int[] pixels = new int[width * height];bitmap.getPixels(pixels, 0, width, 0, 0, width, height);// In order to measure pure decoding speed, we convert the entire image// to a greyscale array// up front, which is the same as the Y channel of the// YUVLuminanceSource in the real app.luminances = new byte[width * height];for (int y = 0; y < height; y++) {int offset = y * width;for (int x = 0; x < width; x++) {int pixel = pixels[offset + x];int r = (pixel >> 16) & 0xff;int g = (pixel >> 8) & 0xff;int b = pixel & 0xff;if (r == g && g == b) {// Image is already greyscale, so pick any channel.luminances[offset + x] = (byte) r;} else {// Calculate luminance cheaply, favoring green.luminances[offset + x] = (byte) ((r + g + g + b) >> 2);}}}}@Overridepublic byte[] getRow(int y, byte[] row) {if (y < 0 || y >= getHeight()) {throw new IllegalArgumentException("Requested row is outside the image: " + y);}int width = getWidth();if (row == null || row.length < width) {row = new byte[width];}System.arraycopy(luminances, y * width, row, 0, width);return row;}// Since this class does not support cropping, the underlying byte array// already contains// exactly what the caller is asking for, so give it to them without a copy.@Overridepublic byte[] getMatrix() {return luminances;}private static Bitmap loadBitmap(String path) throws FileNotFoundException {Bitmap bitmap = BitmapFactory.decodeFile(path);if (bitmap == null) {throw new FileNotFoundException("Couldn't open " + path);}return bitmap;}}

Main. xml:

Download a QR code jar: core. jar from the Internet.