codeView.js

  return (
            <View style={styles.scrollViewStyle}>
                <Fragment>
                    <StatusBar barStyle="dark-content" />
                    <Text style={styles.textTitle}>Welcome To React-Native QR Code Tutorial !</Text>
                    {!scan && !ScanResult &&
                        <View style={styles.cardView} >
                            <Text numberOfLines={8} style={styles.descText}>{desccription}</Text>

                            <TouchableOpacity onPress={this.activeQR} style={styles.buttonTouchable}>
                                <Text style={styles.buttonTextStyle}>Click to Scan !</Text>
                            </TouchableOpacity>

                        </View>
                    }

                    {ScanResult &&
                        <Fragment>
                            <Text style={styles.textTitle1}>Result !</Text>
                            <View style={ScanResult ? styles.scanCardView : styles.cardView}>
                                <Text>Type : {result.type}</Text>
                                <Text>Result : {result.data}</Text>
                                <Text numberOfLines={1}>RawData: {result.rawData}</Text>
                                <TouchableOpacity onPress={this.scanAgain} style={styles.buttonTouchable}>
                                    <Text style={styles.buttonTextStyle}>Click to Scan again!</Text>
                                </TouchableOpacity>

                            </View>
                        </Fragment>
                    }


                    {scan &&
                        <QRCodeScanner
                            reactivate={true}
                            showMarker={true}
                            ref={(node) => { this.scanner = node }}
                            onRead={this.onSuccess}
                            topContent={
                                <Text style={styles.centerText}>
                                    Go to <Text style={styles.textBold}>wikipedia.org/wiki/QR_code</Text> on your computer and scan the QR code to test.</Text>
                            }
                            bottomContent={
                                <View>
                                    <TouchableOpacity style={styles.buttonTouchable} onPress={() => this.scanner.reactivate()}>
                                        <Text style={styles.buttonTextStyle}>OK. Got it!</Text>
                                    </TouchableOpacity>

                                    <TouchableOpacity style={styles.buttonTouchable} onPress={() => this.setState({ scan: false })}>
                                        <Text style={styles.buttonTextStyle}>Stop Scan</Text>
                                    </TouchableOpacity>
                                </View>

                            }
                        />
                    }
                </Fragment>
            </View>

        );