Как создать и показать код Qr в приложении для Android

Question

не могли бы вы мне помочь. Я хочу написать небольшое приложение для Android, в котором есть одна кнопка. Когда вы его нажимаете, он должен показать вам qr-код. Код Qr должен быть сгенерирован из некоторой строки.

судимый до сих пор:

public void onClick(View v){ 
    QRCodeEncoder qrCodeEncoder = new QRCodeEncoder("Hello", 
     null, 
     Contents.Type.TEXT, 
     BarcodeFormat.QR_CODE.toString(), 
     smallerDimension); 
    Bitmap bitmap = qrCodeEncoder.encodeAsBitmap(); 
} 

Answer 1

сначала вам нужно будет добавить zing2.1.jar файлов в проекте затем сделать следующий код

QRCodeEncoder.java

public final class QRCodeEncoder { 
    private static final int WHITE = 0xFFFFFFFF; 
    private static final int BLACK = 0xFF000000; 

    private int dimension = Integer.MIN_VALUE; 
    private String contents = null; 
    private String displayContents = null; 
    private String title = null; 
    private BarcodeFormat format = null; 
    private boolean encoded = false; 

    public QRCodeEncoder(String data, Bundle bundle, String type, String format, int dimension) { 
     this.dimension = dimension; 
     encoded = encodeContents(data, bundle, type, format); 
    } 

    public String getContents() { 
     return contents; 
    } 

    public String getDisplayContents() { 
     return displayContents; 
    } 

    public String getTitle() { 
     return title; 
    } 

    private boolean encodeContents(String data, Bundle bundle, String type, String formatString) { 
     // Default to QR_CODE if no format given. 
     format = null; 
     if (formatString != null) { 
      try { 
       format = BarcodeFormat.valueOf(formatString); 
      } catch (IllegalArgumentException iae) { 
       // Ignore it then 
      } 
     } 
     if (format == null || format == BarcodeFormat.QR_CODE) { 
      this.format = BarcodeFormat.QR_CODE; 
      encodeQRCodeContents(data, bundle, type); 
     } else if (data != null && data.length() > 0) { 
      contents = data; 
      displayContents = data; 
      title = "Text"; 
     } 
     return contents != null && contents.length() > 0; 
    } 

    private void encodeQRCodeContents(String data, Bundle bundle, String type) { 
     if (type.equals(Contents.Type.TEXT)) { 
      if (data != null && data.length() > 0) { 
       contents = data; 
       displayContents = data; 
       title = "Text"; 
      } 
     } else if (type.equals(Contents.Type.EMAIL)) { 
      data = trim(data); 
      if (data != null) { 
       contents = "mailto:" + data; 
       displayContents = data; 
       title = "E-Mail"; 
      } 
     } else if (type.equals(Contents.Type.PHONE)) { 
      data = trim(data); 
      if (data != null) { 
       contents = "tel:" + data; 
       displayContents = PhoneNumberUtils.formatNumber(data); 
       title = "Phone"; 
      } 
     } else if (type.equals(Contents.Type.SMS)) { 
      data = trim(data); 
      if (data != null) { 
       contents = "sms:" + data; 
       displayContents = PhoneNumberUtils.formatNumber(data); 
       title = "SMS"; 
      } 
     } else if (type.equals(Contents.Type.CONTACT)) { 
      if (bundle != null) { 
       StringBuilder newContents = new StringBuilder(100); 
       StringBuilder newDisplayContents = new StringBuilder(100); 

       newContents.append("MECARD:"); 

       String name = trim(bundle.getString(ContactsContract.Intents.Insert.NAME)); 
       if (name != null) { 
        newContents.append("N:").append(escapeMECARD(name)).append(';'); 
        newDisplayContents.append(name); 
       } 

       String address = trim(bundle.getString(ContactsContract.Intents.Insert.POSTAL)); 
       if (address != null) { 
        newContents.append("ADR:").append(escapeMECARD(address)).append(';'); 
        newDisplayContents.append('\n').append(address); 
       } 

       Collection<String> uniquePhones = new HashSet<String>(Contents.PHONE_KEYS.length); 
       for (int x = 0; x < Contents.PHONE_KEYS.length; x++) { 
        String phone = trim(bundle.getString(Contents.PHONE_KEYS[x])); 
        if (phone != null) { 
         uniquePhones.add(phone); 
        } 
       } 
       for (String phone : uniquePhones) { 
        newContents.append("TEL:").append(escapeMECARD(phone)).append(';'); 
        newDisplayContents.append('\n').append(PhoneNumberUtils.formatNumber(phone)); 
       } 

       Collection<String> uniqueEmails = new HashSet<String>(Contents.EMAIL_KEYS.length); 
       for (int x = 0; x < Contents.EMAIL_KEYS.length; x++) { 
        String email = trim(bundle.getString(Contents.EMAIL_KEYS[x])); 
        if (email != null) { 
         uniqueEmails.add(email); 
        } 
       } 
       for (String email : uniqueEmails) { 
        newContents.append("EMAIL:").append(escapeMECARD(email)).append(';'); 
        newDisplayContents.append('\n').append(email); 
       } 

       String url = trim(bundle.getString(Contents.URL_KEY)); 
       if (url != null) { 
        // escapeMECARD(url) -> wrong escape e.g. http\://zxing.google.com 
        newContents.append("URL:").append(url).append(';'); 
        newDisplayContents.append('\n').append(url); 
       } 

       String note = trim(bundle.getString(Contents.NOTE_KEY)); 
       if (note != null) { 
        newContents.append("NOTE:").append(escapeMECARD(note)).append(';'); 
        newDisplayContents.append('\n').append(note); 
       } 

       // Make sure we've encoded at least one field. 
       if (newDisplayContents.length() > 0) { 
        newContents.append(';'); 
        contents = newContents.toString(); 
        displayContents = newDisplayContents.toString(); 
        title = "Contact"; 
       } else { 
        contents = null; 
        displayContents = null; 
       } 

      } 
     } else if (type.equals(Contents.Type.LOCATION)) { 
      if (bundle != null) { 
       // These must use Bundle.getFloat(), not getDouble(), it's part of the API. 
       float latitude = bundle.getFloat("LAT", Float.MAX_VALUE); 
       float longitude = bundle.getFloat("LONG", Float.MAX_VALUE); 
       if (latitude != Float.MAX_VALUE && longitude != Float.MAX_VALUE) { 
        contents = "geo:" + latitude + ',' + longitude; 
        displayContents = latitude + "," + longitude; 
        title = "Location"; 
       } 
      } 
     } 
    } 

    public Bitmap encodeAsBitmap() throws WriterException { 
     if (!encoded) return null; 

     Map<EncodeHintType, Object> hints = null; 
     String encoding = guessAppropriateEncoding(contents); 
     if (encoding != null) { 
      hints = new EnumMap<EncodeHintType, Object>(EncodeHintType.class); 
      hints.put(EncodeHintType.CHARACTER_SET, encoding); 
     } 
     MultiFormatWriter writer = new MultiFormatWriter(); 
     BitMatrix result = writer.encode(contents, format, dimension, dimension, hints); 
     int width = result.getWidth(); 
     int height = result.getHeight(); 
     int[] pixels = new int[width * height]; 
     // All are 0, or black, by default 
     for (int y = 0; y < height; y++) { 
      int offset = y * width; 
      for (int x = 0; x < width; x++) { 
       pixels[offset + x] = result.get(x, y) ? BLACK : WHITE; 
      } 
     } 

     Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); 
     bitmap.setPixels(pixels, 0, width, 0, 0, width, height); 
     return bitmap; 
    } 

    private static String guessAppropriateEncoding(CharSequence contents) { 
     // Very crude at the moment 
     for (int i = 0; i < contents.length(); i++) { 
      if (contents.charAt(i) > 0xFF) { return "UTF-8"; } 
     } 
     return null; 
    } 

    private static String trim(String s) { 
     if (s == null) { return null; } 
     String result = s.trim(); 
     return result.length() == 0 ? null : result; 
    } 

    private static String escapeMECARD(String input) { 
     if (input == null || (input.indexOf(':') < 0 && input.indexOf(';') < 0)) { return input; } 
     int length = input.length(); 
     StringBuilder result = new StringBuilder(length); 
     for (int i = 0; i < length; i++) { 
      char c = input.charAt(i); 
      if (c == ':' || c == ';') { 
       result.append('\\'); 
      } 
      result.append(c); 
     } 
     return result.toString(); 
    } 
} 

Содержание.java

import android.provider.ContactsContract; 

public final class Contents { 
    private Contents() { 
    } 

    public static final class Type { 

    // Plain text. Use Intent.putExtra(DATA, string). This can be used for URLs too, but string 
    // must include "http://" or "https://". 
     public static final String TEXT = "TEXT_TYPE"; 

     // An email type. Use Intent.putExtra(DATA, string) where string is the email address. 
     public static final String EMAIL = "EMAIL_TYPE"; 

     // Use Intent.putExtra(DATA, string) where string is the phone number to call. 
     public static final String PHONE = "PHONE_TYPE"; 

     // An SMS type. Use Intent.putExtra(DATA, string) where string is the number to SMS. 
     public static final String SMS = "SMS_TYPE"; 


    // A contact. Send a request to encode it as follows: 
    // <p/> 
    // import android.provider.Contacts; 
    // <p/> 
    // Intent intent = new Intent(Intents.Encode.ACTION); intent.putExtra(Intents.Encode.TYPE, 
    // CONTACT); Bundle bundle = new Bundle(); bundle.putString(Contacts.Intents.Insert.NAME, 
    // "Jenny"); bundle.putString(Contacts.Intents.Insert.PHONE, "8675309"); 
    // bundle.putString(Contacts.Intents.Insert.EMAIL, "jenny@the80s.com"); 
    // bundle.putString(Contacts.Intents.Insert.POSTAL, "123 Fake St. San Francisco, CA 94102"); 
    // intent.putExtra(Intents.Encode.DATA, bundle); 

     public static final String CONTACT = "CONTACT_TYPE"; 


    // A geographic location. Use as follows: 
    // Bundle bundle = new Bundle(); 
    // bundle.putFloat("LAT", latitude); 
    // bundle.putFloat("LONG", longitude); 
    // intent.putExtra(Intents.Encode.DATA, bundle); 

     public static final String LOCATION = "LOCATION_TYPE"; 

     private Type() { 
     } 
    } 

    public static final String URL_KEY = "URL_KEY"; 

    public static final String NOTE_KEY = "NOTE_KEY"; 

    // When using Type.CONTACT, these arrays provide the keys for adding or retrieving multiple 
    // phone numbers and addresses. 
    public static final String[] PHONE_KEYS = { 
      ContactsContract.Intents.Insert.PHONE, ContactsContract.Intents.Insert.SECONDARY_PHONE, 
      ContactsContract.Intents.Insert.TERTIARY_PHONE 
    }; 

    public static final String[] PHONE_TYPE_KEYS = { 
      ContactsContract.Intents.Insert.PHONE_TYPE, 
      ContactsContract.Intents.Insert.SECONDARY_PHONE_TYPE, 
      ContactsContract.Intents.Insert.TERTIARY_PHONE_TYPE 
    }; 

    public static final String[] EMAIL_KEYS = { 
      ContactsContract.Intents.Insert.EMAIL, ContactsContract.Intents.Insert.SECONDARY_EMAIL, 
      ContactsContract.Intents.Insert.TERTIARY_EMAIL 
    }; 

    public static final String[] EMAIL_TYPE_KEYS = { 
      ContactsContract.Intents.Insert.EMAIL_TYPE, 
      ContactsContract.Intents.Insert.SECONDARY_EMAIL_TYPE, 
      ContactsContract.Intents.Insert.TERTIARY_EMAIL_TYPE 
    }; 
} 

ли код, приведенный ниже, чтобы добавить строку и установить его в ImageView

String qrData = "Name : "+name+"\n Company : "+comp; 
     int qrCodeDimention = 500; 

     QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(qrData, null, 
       Contents.Type.TEXT, BarcodeFormat.QR_CODE.toString(), qrCodeDimention); 

     try { 
      Bitmap bitmap = qrCodeEncoder.encodeAsBitmap(); 
      imageView.setImageBitmap(bitmap); 
     } catch (WriterException e) { 
      e.printStackTrace(); 
     } 

Answer 2

Я не знаю, какие библиотеки вы используете. Я звоню в свою библиотеку zxing QRReaderActivity в моем приложении.

startActivity(QRReaderActivity.class); 

метод

private void startActivity(Class<?> className) { 
    Intent intent = new Intent(this, className); 
    startActivityForResult(intent, 0); 
}