Android implémente la génération de code QR basée sur Google Zxing-javaDidacticiel-php.cn

Un projet récent utilisait la génération et la reconnaissance de codes QR. Je n'avais jamais été exposé à cela auparavant, j'ai donc cherché en ligne et découvert qu'il existe de nombreuses ressources dans ce domaine, notamment l'encapsulation des codes QR par Google Zxing, qui a été implémenté. Pas mal, vous pouvez le citer directement. Après avoir téléchargé leur code source, je n'ai apporté que quelques modifications, c'est-à-dire ajouter la fonction de reconnaissance des appuis longs à la démo. Internet, beaucoup d'entre eux ne peuvent pas être téléchargés. Exécutez-le, puis résumez-le et ajoutez-le à la démo ci-dessous.
Présentons la classe principale de cette démo

public class BarCodeTestActivity extends Activity { 
   
private TextView resultTextView; 
private EditText qrStrEditText; 
private ImageView qrImgImageView; 
private String time; 
 private File file = null; 
 @Override
 public void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.main);   
  resultTextView = (TextView) this.findViewById(R.id.tv_scan_result); 
  qrStrEditText = (EditText) this.findViewById(R.id.et_qr_string); 
  qrImgImageView = (ImageView) this.findViewById(R.id.iv_qr_image); 
    
  Button scanBarCodeButton = (Button) this.findViewById(R.id.btn_scan_barcode); 
  scanBarCodeButton.setOnClickListener(new OnClickListener() { 
  
@Override
public void onClick(View v) { 
//打开扫描界面扫描条形码或二维码 
Intent openCameraIntent = new Intent(BarCodeTestActivity.this,CaptureActivity.class); 
startActivityForResult(openCameraIntent, 0); 
} 
}); 
qrImgImageView.setOnLongClickListener(new OnLongClickListener() { 
  
@Override
public boolean onLongClick(View v) { 
// 长按识别二维码 
  
 saveCurrentImage(); 
return true; 
} 
});   
  Button generateQRCodeButton = (Button) this.findViewById(R.id.btn_add_qrcode); 
  generateQRCodeButton.setOnClickListener(new OnClickListener() { 
  
@Override
public void onClick(View v) { 
try { 
String contentString = qrStrEditText.getText().toString(); 
if (!contentString.equals("")) { 
//根据字符串生成二维码图片并显示在界面上，第二个参数为图片的大小（350*350） 
Bitmap qrCodeBitmap = EncodingHandler.createQRCode(contentString, 350); 
qrImgImageView.setImageBitmap(qrCodeBitmap); 
}else { 
//提示文本不能是空的 
Toast.makeText(BarCodeTestActivity.this, "Text can not be empty", Toast.LENGTH_SHORT).show(); 
} 
  
} catch (WriterException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} 
}); 
 } 
  
 //这种方法状态栏是空白，显示不了状态栏的信息 
 private void saveCurrentImage() 
 { 
  //获取当前屏幕的大小 
  int width = getWindow().getDecorView().getRootView().getWidth(); 
  int height = getWindow().getDecorView().getRootView().getHeight(); 
  //生成相同大小的图片 
  Bitmap temBitmap = Bitmap.createBitmap( width, height, Bitmap.Config.ARGB_8888 ); 
  //找到当前页面的根布局 
  View view = getWindow().getDecorView().getRootView(); 
  //设置缓存 
  view.setDrawingCacheEnabled(true); 
  view.buildDrawingCache(); 
  //从缓存中获取当前屏幕的图片,创建一个DrawingCache的拷贝，因为DrawingCache得到的位图在禁用后会被回收 
  temBitmap = view.getDrawingCache(); 
  SimpleDateFormat df = new SimpleDateFormat("yyyymmddhhmmss"); 
  time = df.format(new Date()); 
  if(Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())){ 
   file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/screen",time + ".png"); 
   if(!file.exists()){ 
    file.getParentFile().mkdirs(); 
    try { 
     file.createNewFile(); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
   } 
   FileOutputStream fos = null; 
   try { 
    fos = new FileOutputStream(file); 
    temBitmap.compress(Bitmap.CompressFormat.PNG, 100, fos); 
    fos.flush(); 
    fos.close(); 
   } catch (FileNotFoundException e) { 
    e.printStackTrace(); 
   } catch (IOException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
   } 
   new Thread(new Runnable() { 
    @Override
    public void run() { 
     String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/screen/" + time + ".png"; 
     final Result result = parseQRcodeBitmap(path); 
     runOnUiThread(new Runnable() { 
      public void run() { 
      if(null!=result){ 
      resultTextView.setText(result.toString()); 
      }else{ 
       Toast.makeText(BarCodeTestActivity.this, "无法识别", Toast.LENGTH_LONG).show(); 
      } 
      } 
     }); 
    } 
   }).start(); 
   //禁用DrawingCahce否则会影响性能 ,而且不禁止会导致每次截图到保存的是缓存的位图 
   view.setDrawingCacheEnabled(false); 
  } 
 } 
   
 //解析二维码图片,返回结果封装在Result对象中 
 private com.google.zxing.Result parseQRcodeBitmap(String bitmapPath){ 
  //解析转换类型UTF-8 
  Hashtable<DecodeHintType, String> hints = new Hashtable<DecodeHintType, String>(); 
  hints.put(DecodeHintType.CHARACTER_SET, "utf-8"); 
  //获取到待解析的图片 
  BitmapFactory.Options options = new BitmapFactory.Options();  
  //如果我们把inJustDecodeBounds设为true，那么BitmapFactory.decodeFile(String path, Options opt) 
  //并不会真的返回一个Bitmap给你，它仅仅会把它的宽，高取回来给你 
  options.inJustDecodeBounds = true; 
  //此时的bitmap是null，这段代码之后，options.outWidth 和 options.outHeight就是我们想要的宽和高了 
  Bitmap bitmap = BitmapFactory.decodeFile(bitmapPath,options); 
  //我们现在想取出来的图片的边长（二维码图片是正方形的）设置为400像素 
  /** 
   options.outHeight = 400; 
   options.outWidth = 400; 
   options.inJustDecodeBounds = false; 
   bitmap = BitmapFactory.decodeFile(bitmapPath, options); 
  */
  //以上这种做法，虽然把bitmap限定到了我们要的大小，但是并没有节约内存，如果要节约内存，我们还需要使用inSimpleSize这个属性 
  options.inSampleSize = options.outHeight / 400; 
  if(options.inSampleSize <= 0){ 
   options.inSampleSize = 1; //防止其值小于或等于0 
  } 
  /** 
   * 辅助节约内存设置 
   * 
   * options.inPreferredConfig = Bitmap.Config.ARGB_4444; // 默认是Bitmap.Config.ARGB_8888 
   * options.inPurgeable = true; 
   * options.inInputShareable = true; 
   */
  options.inJustDecodeBounds = false; 
  bitmap = BitmapFactory.decodeFile(bitmapPath, options);  
  //新建一个RGBLuminanceSource对象，将bitmap图片传给此对象 
  RGBLuminanceSource rgbLuminanceSource = new RGBLuminanceSource(bitmap); 
  //将图片转换成二进制图片 
  BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(rgbLuminanceSource)); 
  //初始化解析对象 
  QRCodeReader reader = new QRCodeReader(); 
  //开始解析 
  Result result = null; 
  try { 
   result = reader.decode(binaryBitmap, hints); 
  } catch (Exception e) { 
   // TODO: handle exception 
  } 
    
  return result; 
 } 
  
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
super.onActivityResult(requestCode, resultCode, data); 
//处理扫描结果（在界面上显示） 
if (resultCode == RESULT_OK) { 
Bundle bundle = data.getExtras(); 
String scanResult = bundle.getString("result"); 
resultTextView.setText(scanResult); 
} 
} 
}

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Ensuite, le code QR de reconnaissance par appui long appelle la classe RGBLuminanceSource

public class RGBLuminanceSource extends LuminanceSource { 
private byte bitmapPixels[]; 
  
protected RGBLuminanceSource(Bitmap bitmap) { 
super(bitmap.getWidth(), bitmap.getHeight()); 
  
// 首先，要取得该图片的像素数组内容 
int[] data = new int[bitmap.getWidth() * bitmap.getHeight()]; 
this.bitmapPixels = new byte[bitmap.getWidth() * bitmap.getHeight()]; 
bitmap.getPixels(data, 0, getWidth(), 0, 0, getWidth(), getHeight()); 
  
// 将int数组转换为byte数组，也就是取像素值中蓝色值部分作为辨析内容 
for (int i = 0; i < data.length; i++) { 
this.bitmapPixels[i] = (byte) data[i]; 
} 
} 
  
@Override
public byte[] getMatrix() { 
// 返回我们生成好的像素数据 
return bitmapPixels; 
} 
  
  
@Override
public byte[] getRow(int y, byte[] row) { 
// 这里要得到指定行的像素数据 
System.arraycopy(bitmapPixels, y * getWidth(), row, 0, getWidth()); 
return row; 
} 
}

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Le code QR de reconnaissance de la caméra appelle la classe CaptureActivity

public class CaptureActivity extends Activity implements Callback { 
  
private CaptureActivityHandler handler; 
private ViewfinderView viewfinderView; 
private boolean hasSurface; 
private Vector<BarcodeFormat> decodeFormats; 
private String characterSet; 
private InactivityTimer inactivityTimer; 
private MediaPlayer mediaPlayer; 
private boolean playBeep; 
private static final float BEEP_VOLUME = 0.10f; 
private boolean vibrate; 
private Button cancelScanButton; 
  
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.camera); 
  
CameraManager.init(getApplication()); 
viewfinderView = (ViewfinderView) findViewById(R.id.viewfinder_view); 
cancelScanButton = (Button) this.findViewById(R.id.btn_cancel_scan); 
hasSurface = false; 
inactivityTimer = new InactivityTimer(this); 
} 
  
@Override
protected void onResume() { 
super.onResume(); 
SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view); 
SurfaceHolder surfaceHolder = surfaceView.getHolder(); 
if (hasSurface) { 
initCamera(surfaceHolder); 
} else { 
surfaceHolder.addCallback(this); 
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 
} 
decodeFormats = null; 
characterSet = null; 
  
  
playBeep = true; 
AudioManager audioService = (AudioManager) getSystemService(AUDIO_SERVICE); 
if (audioService.getRingerMode() != AudioManager.RINGER_MODE_NORMAL) { 
playBeep = false; 
} 
initBeepSound(); 
vibrate = true; 
  
//quit the scan view 
cancelScanButton.setOnClickListener(new OnClickListener() { 
  
@Override
public void onClick(View v) { 
CaptureActivity.this.finish(); 
} 
}); 
} 
  
@Override
protected void onPause() { 
super.onPause(); 
if (handler != null) { 
handler.quitSynchronously(); 
handler = null; 
} 
CameraManager.get().closeDriver(); 
} 
  
@Override
protected void onDestroy() { 
inactivityTimer.shutdown(); 
super.onDestroy(); 
} 
  
/** 
* Handler scan result 
* @param result 
* @param barcode 
*/
public void handleDecode(Result result, Bitmap barcode) { 
inactivityTimer.onActivity(); 
playBeepSoundAndVibrate(); 
String resultString = result.getText(); 
//FIXME 
if (resultString.equals("")) { 
//扫描失败 
Toast.makeText(CaptureActivity.this, "Scan failed!", Toast.LENGTH_SHORT).show(); 
}else { 
// System.out.println("Result:"+resultString); 
Intent resultIntent = new Intent(); 
Bundle bundle = new Bundle(); 
bundle.putString("result", resultString); 
resultIntent.putExtras(bundle); 
this.setResult(RESULT_OK, resultIntent); 
} 
CaptureActivity.this.finish(); 
} 
  
private void initCamera(SurfaceHolder surfaceHolder) { 
try { 
CameraManager.get().openDriver(surfaceHolder); 
} catch (IOException ioe) { 
return; 
} catch (RuntimeException e) { 
return; 
} 
if (handler == null) { 
handler = new CaptureActivityHandler(this, decodeFormats, 
characterSet); 
} 
} 
  
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, 
int height) { 
  
} 
  
@Override
public void surfaceCreated(SurfaceHolder holder) { 
if (!hasSurface) { 
hasSurface = true; 
initCamera(holder); 
} 
  
} 
  
@Override
public void surfaceDestroyed(SurfaceHolder holder) { 
hasSurface = false; 
} 
public ViewfinderView getViewfinderView() { 
return viewfinderView; 
}  
public Handler getHandler() { 
return handler; 
}  
public void drawViewfinder() { 
viewfinderView.drawViewfinder(); 
} 
private void initBeepSound() { 
if (playBeep && mediaPlayer == null) { 
// The volume on STREAM_SYSTEM is not adjustable, and users found it 
// too loud, 
// so we now play on the music stream. 
setVolumeControlStream(AudioManager.STREAM_MUSIC); 
mediaPlayer = new MediaPlayer(); 
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); 
mediaPlayer.setOnCompletionListener(beepListener); 
  
AssetFileDescriptor file = getResources().openRawResourceFd( 
R.raw.beep); 
try { 
mediaPlayer.setDataSource(file.getFileDescriptor(), 
file.getStartOffset(), file.getLength()); 
file.close(); 
mediaPlayer.setVolume(BEEP_VOLUME, BEEP_VOLUME); 
mediaPlayer.prepare(); 
} catch (IOException e) { 
mediaPlayer = null; 
} 
} 
} 
  
private static final long VIBRATE_DURATION = 200L;  
private void playBeepSoundAndVibrate() { 
if (playBeep && mediaPlayer != null) { 
mediaPlayer.start(); 
} 
if (vibrate) { 
Vibrator vibrator = (Vibrator) getSystemService(VIBRATOR_SERVICE); 
vibrator.vibrate(VIBRATE_DURATION); 
} 
} 
  
/** 
* When the beep has finished playing, rewind to queue up another one. 
*/
private final OnCompletionListener beepListener = new OnCompletionListener() { 
public void onCompletion(MediaPlayer mediaPlayer) { 
mediaPlayer.seekTo(0); 
} 
}; 
  
  
}

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Ce qui suit est le fichier mian de mise en page principal

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:background="@android:color/white"
 android:orientation="vertical" > 
  
  
 <Button
  android:id="@+id/btn_scan_barcode"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_marginTop="30dp"
  android:text="Open camera" /> 
   
 <LinearLayout
  android:orientation="horizontal"
  android:layout_marginTop="10dp"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"> 
    
  <TextView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textColor="@android:color/black"
  android:textSize="18sp"
  android:text="Scan result：" /> 
    
  <TextView
  android:id="@+id/tv_scan_result"
  android:layout_width="fill_parent"
  android:textSize="18sp"
  android:textColor="@android:color/black"
  android:layout_height="wrap_content" /> 
 </LinearLayout> 
   
 <EditText
  android:id="@+id/et_qr_string"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_marginTop="30dp"
  android:hint="Input the text"/> 
   
 <Button
  android:id="@+id/btn_add_qrcode"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="Generate QRcode" /> 
   
 <ImageView
  android:id="@+id/iv_qr_image"
  android:layout_width="250dp"
  android:layout_height="250dp"
  android:scaleType="fitXY"
  android:layout_marginTop="10dp"
  android:layout_gravity="center"/> 
  
  
</LinearLayout>

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Pour plus de détails, veuillez télécharger la démo et voyez par vous-même. La démo résout le problème de l'étirement du code QR pendant la verticale. décodage.

Ce qui précède représente l'intégralité du contenu de cet article. J'espère qu'il sera utile à l'apprentissage de chacun. J'espère également que tout le monde soutiendra le site Web PHP chinois.

Pour plus d'articles liés à l'implémentation par Android de la génération de code QR basée sur Google Zxing, veuillez faire attention au site Web PHP chinois !