我的项目有问题。我想在从 JSON 中获取元素后显示它们。当我试图观察 JSON 的内容时,我看到了它,但是当我试图在我的组件中显示它时,它没有出现。此外,调试器不会显示任何错误或问题,并且应用程序编译成功。我真的被困住了,所以我真的需要你们的帮助
App.js 代码:
import React, { Component } from 'react'
import { View, ScrollView, StyleSheet } from 'react-native'
import { Header, ImageCard } from './src/components/uikit'
const url = 'https://s3.eu-central-1.wasabisys.com/ghashtag/RNForKids/00-Init/data.json'
export default class App extends Component {
constructor(props) {
super(props);
this.state = {
title: 'STAR GATE',
data: []
};
}
componentDidMount = async () => {
try {
const response = await fetch(url)
const data = await response.json()
this.setState({ data })
}
catch (e) {
console.log(e)
throw e
}
}
render() {
const { title, data } = this.state
const { container } = style
return (
<View>
<Header title={title} />
<ScrollView>
<View style={container}>
{data.map(item => {
<ImageCard data={item} key={item.id} />
})
}
</View>
</ScrollView>
</View>
)
}
}
const style = StyleSheet.create({
container: {
marginTop: 30,
flexDirection: 'row',
flexWrap: 'wrap',
flexShrink: 2,
justifyContent: 'space-around',
marginBottom: 150,
backgroundColor: 'gold',
width: 150
}
})
我的问题发生在App.js里面
和 ImageCard 代码:
import React from 'react'
import { Image, View, Text, StyleSheet } from 'react-native'
import { h, w } from '../../../constants'
const ImageCard = ({data}) => {
const {container, sub, h2, cover} = styles
const {image, name} = data
return (
<View style={container}>
<View style={sub}>
<Image
style={cover}
source={{
uri: image,
}}
/>
</View>
<Text style={h2}>{name.toUpperCase()}</Text>
</View>
)
}
const styles = StyleSheet.create({
container: {
width: w / 2.1,
paddingVertical: 10,
},
sub: {
padding:10,
shadowColor: 'black',
shadowRadius: 8,
shadowOffset: { width: 0, height: 5 },
shadowOpacity: 0.4,
},
h2: {
fontFamily: 'AvenirNext-DemiBold',
fontSize: 16,
alignSelf: 'center',
textAlign: 'center',
width: w / 2.4
},
cover: {
width: w / 2.4,
height: w * 0.63,
borderRadius: 10
}
})
export { ImageCard }
应该没问题,我是按照向导做的,但是出了点问题。
答案 0 :(得分:2)
看起来你没有从地图返回任何东西!
data.map(item => {
<ImageCard data={item} key={item.id} />
})
应该变成
data.map(item => {
return <ImageCard data={item} key={item.id} />
})
// OR
data.map(item => ( // <-- Note the bracket change
<ImageCard data={item} key={item.id} />
))