Как преобразовать строку в штрих-код

Попробуйте это

compile 'com.google.zxing:core:3.2.1'
compile 'com.journeyapps:zxing-android-embedded:3.2.0@aar'

     String text="" // Whatever you need to encode in the QR code
     MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
     try {
    BitMatrix bitMatrix = multiFormatWriter.encode(text, BarcodeFormat.QR_CODE,200,200);
     BarcodeEncoder barcodeEncoder = new BarcodeEncoder();
     Bitmap bitmap = barcodeEncoder.createBitmap(bitMatrix);
     imageView.setImageBitmap(bitmap);
     } catch (WriterException e) {
     e.printStackTrace();
  }

ОБНОВЛЕНИЕ

, если это не поможет вам попробовать это [ 115]

https://github.com/journeyapps/zxing-android-embedded

Попробуйте это:

В сборке: gradle:

implementation 'com.google.zxing:core:3.2.1'
implementation 'com.journeyapps:zxing-android-embedded:3.2.0@aar'

А затем напишите свой собственный код, как показано ниже.

public class DemoActivity extends AppCompatActivity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        LinearLayout l = new LinearLayout(this);
        l.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT));
        l.setOrientation(LinearLayout.VERTICAL);

        setContentView(l);

        // barcode data
        String barcode_data = "123456viralpatel";

        // barcode image
        Bitmap bitmap = null;
        ImageView iv = new ImageView(this);

        try {

            bitmap = encodeAsBitmap(barcode_data, BarcodeFormat.CODE_128, 600, 300);
            iv.setImageBitmap(bitmap);

        } catch (WriterException e) {
            e.printStackTrace();
        }

        l.addView(iv);

        //barcode text
        TextView tv = new TextView(this);
        tv.setGravity(Gravity.CENTER_HORIZONTAL);
        tv.setText(barcode_data);

        l.addView(tv);

    }
    private static final int WHITE = 0xFFFFFFFF;
    private static final int BLACK = 0xFF000000;

    Bitmap encodeAsBitmap(String contents, BarcodeFormat format, int img_width, int img_height) throws WriterException {
        String contentsToEncode = contents;
        if (contentsToEncode == null) {
            return null;
        }
        Map<EncodeHintType, Object> hints = null;
        String encoding = guessAppropriateEncoding(contentsToEncode);
        if (encoding != null) {
            hints = new EnumMap<>(EncodeHintType.class);
            hints.put(EncodeHintType.CHARACTER_SET, encoding);
        }
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix result;
        try {
            result = writer.encode(contentsToEncode, format, img_width, img_height, hints);
        } catch (IllegalArgumentException iae) {
            // Unsupported format
            return null;
        }
        int width = result.getWidth();
        int height = result.getHeight();
        int[] pixels = new int[width * height];
        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;
    }
}