title: Barcode scanner scans once and shows the same result when scanned for second time
body: <p>I have a react native app in which i'm using react-native-camera and i can scan once and the scan result shows without any issue. But when i go for the second scan it shows the same result.I have my barcode scanner in one tab and after scanning it navigates to a different tab with the result.How can i scan and show results more than once? 
  Here's the barcode scanner tab component i have:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>class BarScannerView extends Component {
  
    constructor(props) {
      super(props);
      this.camera = null;
      this.barcodeCodes = [];
  
      this.state = {
        changeScreen: false,
        camera: {
          type: RNCamera.Constants.Type.back,
          flashMode: RNCamera.Constants.FlashMode.auto,
          barcodeFinderVisible: true
        },
        focusedScreen: false
      };
    }
  
    onBarCodeRead = (scanResult) =&gt; {
      if (scanResult.data !== null) {
        let bacodeScanResult = scanResult.data
        AsyncStorage.setItem('barcodeValue', bacodeScanResult)
        this.props.navigation.navigate('Stock')
      }
      return;
    }
  
    componentDidMount() {
     
      console.log(' BarScanner componentDidMount was called...', this.props)
      const { navigation } = this.props;
      navigation.addListener('willFocus', () =&gt;
        this.setState({ focusedScreen: true })
      );
      navigation.addListener('willBlur', () =&gt;
        this.setState({ focusedScreen: false })
      );
    }
  
    componentWillUnmount() {
      console.log('BarScanner componentWillUnmount was called..')
      this.onBarCodeRead()
    }
  
    render() {
      const { focusedScreen } = this.state;
      if (focusedScreen) { 
        return (
          &lt;View style={styles.container}&gt;
            &lt;RNCamera
              ref={ref =&gt; {
                this.camera = ref;
              }}
              barcodeFinderVisible={this.state.camera.barcodeFinderVisible}
              barcodeFinderWidth={280}
              barcodeFinderHeight={220}
              barcodeFinderBorderColor="white"
              barcodeFinderBorderWidth={2}
              defaultTouchToFocus
              flashMode={this.state.camera.flashMode}
              onBarCodeRead={this.onBarCodeRead}
              onFocusChanged={() =&gt; { }}
              onZoomChanged={() =&gt; { }}
              permissionDialogTitle={'Permission to use camera'}
              permissionDialogMessage={'We need your permission to use your camera phone'}
              style={styles.preview}
              type={this.state.camera.type}
            /&gt;
  
            &lt;View style={[styles.overlay, styles.topOverlay]}&gt;
              &lt;Text style={styles.scanScreenMessage}&gt;Please scan the barcode.&lt;/Text&gt;
            &lt;/View&gt;
  
            &lt;View style={{ position: 'absolute', top: 150, left: '12%' }}&gt;
              &lt;View
                style={{
                  width: 300,
                  height: 300,
                  backgroundColor: 'transparent',
                  borderColor: 'white',
                  borderWidth: 1
                }}
              &gt;
              &lt;/View&gt;
            &lt;/View&gt;
  
            &lt;View style={[styles.overlay, styles.bottomOverlay]}&gt;
              &lt;Button
                disabled
                onPress={() =&gt; { console.log('scan clicked'); }}
                style={styles.enterBarcodeManualButton}
                title="Choose Barcode"
              /&gt;
            &lt;/View&gt;
          &lt;/View&gt;
        );
      } else {
        return &lt;Stock/&gt;
      }
        
      }
    }
  
  
  export default BarScannerView</code></pre>
  </div>
  </div>
  </p>
  
  <p>How can i remove previous result when user goes to this barcode scanner tab for the second time?</p>
  
  <p>Additional info:</p>
  
  <ul>
  <li>React Native version:"0.57.8"</li>
  <li>React Navigation v3</li>
  <li>React-Native-Camera "^1.6.4"</li>
  </ul>