二维码因其便捷性已经被广泛的使用，进行开发的时候客户也经常会提出这样的需求。这里提供了对生成二维码和解析图片二维码的简单封装。

首先在gradle中引入zxing：

compile 'com.google.zxing:core:3.1.0'

 然后是工具类：

/** * 解析二维码的工具类
 * 1.必须在项目中引入zxing * 2.支持生成二维码 * 3.解析图片中的二维码 * 4.把二维码保存到本地 * Created by hsji on 2016/1/14. */public class QRCodeUtils{    private static final String TAG = QRCodeUtils.class.getSimpleName();    public static final String CHARSET_UTF_8 = "UTF-8";    public static final String CHARSET_GBK = "GBK";    /**     * 默认生成方法     *     * @param context     * @param content     * @return     */    public static final Bitmap encodeAsBitmap(Context context, String content)    {        //默认二维码的宽度为屏幕宽度的一半        int size = Math.min(context.getResources().getDisplayMetrics().widthPixels, context.getResources().getDisplayMetrics().heightPixels) / 2;        return encodeAsBitmap(content, CHARSET_UTF_8, size);    }    /**     * 生成二维码     *     * @param content    字符串内容     * @param encodeType 编码格式     * @param size       二维码的尺寸     * @return     */    public static final Bitmap encodeAsBitmap(String content, String encodeType, int size)    {        if (TextUtils.isEmpty(content))        {            return null;        }        Map
     
       hints = null;        hints = new EnumMap<>(EncodeHintType.class);        //指定编码格式        hints.put(EncodeHintType.CHARACTER_SET, encodeType);        //指定纠错等级 L:7%  M:15%  Q:25%  H:30%        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);        BitMatrix result;        try        {            result = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, size, size, hints);        } catch (IllegalArgumentException e)        {            e.printStackTrace();            return null;        } catch (WriterException e)        {            e.printStackTrace();            return null;        }        int[] pixels = new int[size * size];        for (int y = 0; y < size; y++)        {            int offset = y * size;            for (int x = 0; x < size; x++)            {                pixels[offset + x] = result.get(x, y) ? 0x000000 : 0xffffff;            }        }        //没有透明度  节省内存        return Bitmap.createBitmap(pixels, size, size, Bitmap.Config.RGB_565);    }    /**     * 解析二维码     *     * @param path     * @return     */    public static String decode(String path)    {        if (TextUtils.isEmpty(path))        {            return null;        }        Hashtable
      
        hints = new Hashtable
       
        ();        //设置编码格式        hints.put(DecodeHintType.CHARACTER_SET, CHARSET_UTF_8);        Bitmap src = BitmapFactory.decodeFile(path);        int[] pixels = new int[src.getWidth() * src.getHeight()];        src.getPixels(pixels, 0, src.getWidth(), 0, 0, src.getWidth(), src.getHeight());        RGBLuminanceSource source = new RGBLuminanceSource(src.getWidth(), src.getHeight(), pixels);        BinaryBitmap bb = new BinaryBitmap(new HybridBinarizer(source));        MultiFormatReader reader = new MultiFormatReader();        try        {            Result result = reader.decode(bb, hints);            return result.getText();        } catch (NotFoundException e)        {            e.printStackTrace();        }        return null;    }    /**     * 保存二维码到本地
        
     * 直接保存二维码得到的是一张黑图（我也不知道什么原因）     *     * @param src     * @param path     * @return     */    public static final boolean saveQRCode(Bitmap src, String path)    {        Bitmap target = Bitmap.createBitmap(src.getWidth(), src.getHeight(), Bitmap.Config.ARGB_8888);        Canvas canvas = new Canvas(target);        canvas.drawBitmap(src, 0.0f, 0.0f, new Paint());        BufferedOutputStream bos = null;        try        {            File file = new File(path);            if (file.exists())            {                file.delete();            }            bos = new BufferedOutputStream(new FileOutputStream(file));            target.compress(Bitmap.CompressFormat.PNG, 100, bos);        } catch (Exception e)        {            e.printStackTrace();            return false;        } finally        {            if (bos != null)            {                try                {                    bos.flush();                    bos.close();                } catch (Exception e)                {                    e.printStackTrace();                }            }            if (target != null && !target.isRecycled())            {                target.recycle();                target = null;            }        }        return true;    }}
       
      
     

 最后是使用方法：

//生成二维码 显示在ImageView中        iv.setImageBitmap(QRCodeUtils.encodeAsBitmap(this, "https://www.baidu.com"));        //生成二维码并保存   之后在解析此二维码        if (FileUtils.isExternalFileSystemAccessible())        {            if (QRCodeUtils.saveQRCode(QRCodeUtils.encodeAsBitmap(this, "https://www.baidu.com"), Environment.getExternalStorageDirectory() + "/qrcode.png"))            {                Toast.makeText(this, "二维码保存成功！", Toast.LENGTH_SHORT).show();                mTextViewResult.setText(QRCodeUtils.decode(Environment.getExternalStorageDirectory() + "/qrcode.png"));            }        } else        {            Toast.makeText(this, "存储空间暂不可用！", Toast.LENGTH_SHORT).show();        }