How to restart the camera in ZXing after it finds the QR code

Question

When the Zxing finds a QR code it deliver it to handleResult function and it stops the camera. I need to restart the camera if the decoded QR code was already saved in my app. How to restart the camera again?

Answer 1

If you're using ZXing's ZXingScannerView you can use stopCameraPreview() in combination with stopCamera() when you're processing the QR Code and/or showing the result to your users. When your app/user is ready to scan again you just call setResultHandler() with startCamera() and resumeCameraPreview().

Example:

public void startScan() { //use this when you want to resume the camera
    if (scannerView != null) {
        scannerView.setResultHandler(this);
        scannerView.startCamera();
        rescan();
    }
}

public void stopScan() { //use this when you want to stop scanning
// it is very important to do that,
// because the camera will keep scanning codes in background
    if (scannerView != null) {
        scannerView.stopCameraPreview();
        scannerView.stopCamera();
    }
}

public void rescan() {
    if (scannerView != null) {
        scannerView.resumeCameraPreview(this);
    }
}

Hope this helps :)