使用 zxing 進行 QRCode 編碼/解碼

private String readImage(String filename) {
    Bitmap bmp = BitmapFactory.decodeFile(filename);//自動轉換多種圖檔格式 jpg
    LuminanceSource source = new RGBLuminanceSource(bmp);
    BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
    // 解碼
    try {
        Result result = (new QRCodeReader()).decode(bitmap);
        return result.getText();
    } catch (ReaderException e) {
        return "[Error]解碼錯誤";
    }
}

public void encode(String contents, int width, int height) {    
    BitMatrix matrix = null;            
    // 取得資料矩陣
    /*try {//指定編碼
        Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        matrix = new MultiFormatWriter().encode(contents, com.google.zxing.BarcodeFormat.QR_CODE, width, height, hints);   
        onDraw(matrix);
    } catch (com.google.zxing.WriterException e) {
        e.printStackTrace();
    }*/
 
    try {//使用預設編碼
        matrix = new MultiFormatWriter().encode(contents, com.google.zxing.BarcodeFormat.QR_CODE, width, height);
        onDraw(matrix);
    } catch (Exception e) {
        e.printStackTrace();
    }
}
//繪製 QRCode
private void onDraw(BitMatrix matrix) {
    int width = matrix.getWidth();
    int height = matrix.getHeight();
    int rate = 5;
    Paint p = new Paint();
    newb = Bitmap.createBitmap( width*rate, height*rate, Config.ARGB_8888 );  
    Canvas canvasTemp = new Canvas( newb );  
    canvasTemp.drawColor(Color.TRANSPARENT);
    for (int x = 0; x < width; x++) {
        for (int y = 0; y < height; y++) {
            p.setColor(matrix.get(x, y) ? Color.BLACK : Color.WHITE);
            canvasTemp.drawRect(x*rate, y*rate, x*rate+rate, y*rate+rate, p);
        }
    }
    iv.setImageBitmap(newb);
}