React Native“无法加载[端点]：飞行前响应无效（重定向）”

Question

我正在尝试使用127运行React Native应用程序，但是在调试器中出现以下错误：

该应用程序依赖于我确实在react-native run-ios上运行的Django后端。

在应用模拟器中，我看到以下错误：

这与localhost:8000中定义的Timeline组件有关，类似于

timeline.ui.js

-大概是由于控制台中记录的网络错误-export default class Timeline extends Component { renderItem = ({ item, index, section }) => { const formattedTime = formatTime(item.scheduledFor, this.props.timezone); const TimeView = ({ text, icon, color = 'dimgrey' }) => ( <View style={styles.time}> <Image style={[styles.timeIcon, { tintColor: color }]} source={icon} /> <Text style={[styles.timeText, { color }]}>{text}</Text> </View> ); let timeView; let recommended; switch (item.status) { case 'Completed': timeView = <TimeView text={`Completed: ${formattedTime}`} icon={doneIcon} />; break; case 'Scheduled': timeView = <TimeView text={`Scheduled: ${formattedTime}`} icon={doneIcon} />; break; case 'Times Requested': if (item.schedulingNotes.length > 0) { timeView = <TimeView text="Reschedule Request Received" icon={pendingIcon} />; } else { timeView = <TimeView text={`Requested: ${item.requestedTimeframe}`} icon={pendingIcon} />; } break; case 'Times Provided': timeView = <TimeView text="Times available - please select a time" icon={pendingIcon} color={COLOR_PRIMARY} />; break; default: if (item.recommended) { recommended = ( <View style={{ flexDirection: 'row', flex: 1, alignItems: 'center', marginBottom: 5, }} > <Image style={{ tintColor: COLOR_PRIMARY, height: 10, width: 10 }} source={starIcon} /> <Text style={[styles.timeText, { color: COLOR_PRIMARY }]}>Recommended</Text> </View> ); } } return ( <View style={styles.row} key={index}> <View style={styles.details}> <TouchableOpacity onPress={() => this.props.onSessionClicked(section.key, index)}> <View style={styles.innerDetails}> <View style={{ flexDirection: 'row' }}> <View style={[styles.circle, { backgroundColor: COLORS[item.sessionType.categoryName] }]}> <Image style={{ height: ICON_SIZE[item.sessionType.categoryName], width: ICON_SIZE[item.sessionType.categoryName], tintColor: COLOR_WHITE, }} source={ICONS[item.sessionType.categoryName]} /> </View> <View style={{ flexDirection: 'column', flex: 1 }}> {recommended} <Timeline.ItemTitle item={item} /> {timeView} <Markdown>{item.sessionType.shortDescription}</Markdown> </View> </View> </View> </TouchableOpacity> </View> </View> ); }; render() { let listView; if (this.props.error) { listView = ( <View style={styles.error}> <Image resizeMode={Image.resizeMode.contain} source={logoGreenIcon} /> <View style={styles.errorMessage}> <Text style={styles.errorMessageText}>{'Apologies!\nSomething went wrong with your plan. Our team has been notified and you’ll be hearing from us soon. You can also contact us via the "Message Your Guide" button'}</Text> </View> </View>); } else if (this.props.loading) { listView = ( <View style={styles.error}> <ActivityIndicator size="large" /> </View>); } else { let text = moment().format('dddd, MMM D, YYYY'); if (this.props.sessionsRemaining && this.props.sessionsTotal) { text = `${this.props.sessionsRemaining} out of ${this.props.sessionsTotal} sessions remaining`; } listView = ( <View style={styles.subContainer}> <Text style={styles.textRemaining}>{text}</Text> { this.props.checkIn && ( <CheckIn key={this.props.checkIn.id} id={this.props.checkIn.id} title={this.props.checkIn.titleWithDefault} onPress={() => this.props.onCheckInPress(this.props.checkIn.id)} /> ) } { this.props.feedbackRequested.map(session => ( <Feedback key={session.id} sessionId={session.id} sessionName={session.sessionType.title} expertName={session.expert ? session.expert.name : ''} onSubmit={this.props.onFeedbackSubmit} /> )) } <SectionList refreshControl={ <RefreshControl refreshing={this.props.refreshing} onRefresh={() => this.props.refreshTimeline(true)} /> } stickySectionHeadersEnabled contentContainerStyle={styles.listContainer} renderSectionHeader={this.renderSectionHeader} renderItem={this.renderItem} keyExtractor={(item, index) => index} sections={this.props.timeline.map((bucket, index) => ({ data: bucket.sessions, title: bucket.title, key: index }))} /> </View>); } return ( <View style={styles.container}> {listView} <IntercomButton /> </View> ); } } } 是item.sessionType，导致出现了undefined。

但是，相对于React Native来说还比较陌生，我正在努力寻找如何开始调试此问题的方法。任何想法可能是什么问题？