android实现扫码枪功能

 /**
     * 扫码枪扫码处理
     */
    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            int keyCode = event.getKeyCode();
            char aChar = (char) event.getUnicodeChar();
            if (aChar != 0) {
                mStringBufferResult.append(aChar);
            }
            mHandler.removeCallbacks(mScanningFishedRunnable);
            //若为回车键，直接返回
            if (keyCode == KeyEvent.KEYCODE_ENTER) {
                mHandler.post(mScanningFishedRunnable);
            } else {
                //延迟post，若500ms内，有其他事件
                mHandler.postDelayed(mScanningFishedRunnable, 500L);
            }
            return true;
        }
        return super.dispatchKeyEvent(event);
    }

 /**
 * 二维码信息对象
 */
   private QRCode qrCodeBean;
   /**
   * 二维码信息原始数据容器
   */
   private StringBuilder mStringBufferResult = new StringBuilder();
   private Handler mHandler = new Handler();
   
   private Runnable mScanningFishedRunnable = new Runnable() {
        @Override
        public void run() {
            scanOk = false;
            String qrcode = mStringBufferResult.toString();
            if (!TextUtils.isEmpty(qrcode)) {
                // 扫码确定参数
                Gson gson = new Gson();
                try {
                    qrCodeBean = gson.fromJson(qrcode, QRCode.class);
                    // 你的代码...
                    // 如果要支持中文，数据用可以URLEncoder/URLDecoder编解码
                } catch (JsonSyntaxException e) {
                    // 解析失败...
                } catch (UnsupportedEncodingException e) {
                    // 解码失败...
                } finally {
                    mStringBufferResult.setLength(0);
                }
            }
        }
    };