Android 二维码扫描(仿微信界面),根据Google zxing

Android 二维码扫描(仿微信界面),根据Google zxing

Android项目开发中经常会用到二维码扫描,例如登陆、支付等谷歌方面已经有了一个开源库（地址： https://github.com/zxing/zxing）,里面的内容还是比较多的，如果想深入学习这方面的内容，还是不错的。当然了还是要根据实际需求去选择，所以我们就选择类库中的核心Jar包就行了（地址：https://github.com/ASCN-BJ/ZhaoYun/blob/master/qrcodelibrary/libs/core-3.3.1.jar）。
GoogleZxing中的原装的类库有一个问题就是竖屏的时候会导致无法识别，原因是竖屏的时候没有对相机的预览效果进行处理，所以在项目中，进行了处理，使得竖屏的时候的识别能够成功。所以正好看了一下，就当学习了。
效果图



- 二维码的扫描
zxing中的二维码识别界面主要是在CaptureActivity中，基本原理通过获取相机的预览界面然后对获取到的数据进行处理，预览效果是在PreviewCallback中获取数据，然后通过DecodeHandler发送数据,具体识别是在DecodeHandler类中处理。

      @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        Point cameraResolution = configManager.getCameraResolution();
        Handler thePreviewHandler = previewHandler;
//        if (cameraResolution != null && thePreviewHandler != null) {
   
   
//            Message message = thePreviewHandler.obtainMessage(previewMessage, cameraResolution.x,
//                    cameraResolution.y, data);
//            message.sendToTarget();
//            previewHandler = null;
//        } else {
   
   
//            Log.d(TAG, "Got preview callback, but no handler or resolution available");
//        }
//        Log.d(TAG, "onPreviewFrame: " + "onRunning");
        if (cameraResolution != null && thePreviewHandler != null) {
            //add by tancolo
            Point screenResolution = configManager.getScreenResolution();
            Message message;
            if (screenResolution.x < screenResolution.y) {
                // portrait
                message = thePreviewHandler.obtainMessage(previewMessage, cameraResolution.y,
                        cameraResolution.x, data);
            } else {
                // landscape
                message = thePreviewHandler.obtainMessage(previewMessage, cameraResolution.x,
                        cameraResolution.y, data);
            }
            message.sendToTarget();
            previewHandler = null;
        }
    }

可以看到在onPreviewFrame中将具体byte[] data数据发送出去，同时将预览效果的宽高发送出去，用于后续的处理。
接下来看具体二维码识别的代码

  @Override
    public void handleMessage(Message message) {
        if (message == null || !running) {
            return;
        }
        if (message.what == R.id.decode) {
            decode((byte[]) message.obj, message.arg1, message.arg2);

        } else if (message.what == R.id.quit) {
            running = false;
            Looper.myLooper().quit();

        }
    }

 private void decode(byte[] data, int width, int height) {
        long start = System.currentTimeMillis();
        //add by tancolo
        if (width < height) {
            // portrait
            byte[] rotatedData = new byte[data.length];
            for (int x = 0; x < width; x++) {
                for (int y = 0; y < height; y++)
                    rotatedData[y * width + width - x - 1] = data[y + x * height];
            }
            data = rotatedData;
        }
        //end add


        Result rawResult = null;
        PlanarYUVLuminanceSource source =     activity.getCameraManager().buildLuminanceSource(data, width, height);
        if (source != null) {
            BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
            try {
                rawResult = multiFormatReader.decodeWithState(bitmap);//具体识别方法，获取到数据
            } catch (ReaderException re) {
                // continue
            } finally {
                multiFormatReader.reset();
            }
        }

        Handler handler = activity.getHandler();
        if (rawResult != null) {
            // Don't log the barcode contents for security.
            long end = System.currentTimeMillis();
            Log.d(TAG, "Found barcode in " + (end - start) + " ms");
            if (handler != null) {
                Message message = Message.obtain(handler, R.id.decode_succeeded, rawResult);
                Bundle bundle = new Bundle();
                bundleThumbnail(source, bundle);
                message.setData(bundle);
                message.sendToTarget();
            }
        } else {
            if (handler != null) {
                Message message = Message.obtain(handler, R.id.decode_failed);
                message.sendToTarget();
            }
        }
    }

• 二维码的生成

这里写代码片

  try {
mQRCodeEncoder2 = new QRCodeEncoder2(smallerDimension);
 //生成二维码
Bitmap bitmap = mQRCodeEncoder2.encodeAsBitmap(text,    BarcodeFormat.QR_CODE);
 if (bitmap == null) {
 qrCodeEncoder = nul