QRCodeReaderView 是基於 ZXING 條形碼掃描工具專案改進，為了在肖像模式和增強現實目的下進行更簡單的 Android 二維碼檢測。此專案可以在相機的預覽中顯示是否有二維碼。 

用法:

• Create an Activity which implements onQRCodeReadListener, and let implements required methods
• Make sure Activity orientation is PORTRAIT and give Camera permision in the manifest.xml
• Add a "QRCodeReaderView" in the layout editor like you actually do with a button for example

 <com.dlazaro66.qrcodereaderview.QRCodeReaderView
        android:id="@+id/qrdecoderview"         android:layout_width="match_parent"         android:layout_height="match_parent" />

• In your onCreate method, you can find the view as usual, using findViewById() function.
• Set onQRCodeReadListener to the QRCodeReaderView.
• Start & Stop camera preview in onPause() and onResume() overriden methods.
• Use onQRCodeReadListener callbacks as you want.
• You can place widgets or views over QRDecoderView

  public class DecoderActivity extends Activity implements OnQRCodeReadListener {

    private TextView myTextView;
    private QRCodeReaderView mydecoderview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_decoder);

        mydecoderview = (QRCodeReaderView) findViewById(R.id.qrdecoderview);
        mydecoderview.setOnQRCodeReadListener(this);

        myTextView = (TextView) findViewById(R.id.exampleTextView);
    }


    // Called when a QR is decoded
    // "text" : the text encoded in QR
    // "points" : points where QR control points are placed
    @Override
    public void onQRCodeRead(String text, PointF[] points) {
        myTextView.setText(text);
    }


    // Called when your device have no camera
    @Override
    public void cameraNotFound() {

    }

    // Called when there's no QR codes in the camera preview image
    @Override
    public void QRCodeNotFoundOnCamImage() {

    }

    @Override
    protected void onResume() {
        super.onResume();
        mydecoderview.getCameraManager().startPreview();
    }

    @Override
    protected void onPause() {
        super.onPause();
        mydecoderview.getCameraManager().stopPreview();
    }
}