Javascript 如何在React Native中将选择器数据传递到API
我构建了一个React本机组件,可以让您选择几种类型的啤酒,并使用picker将其呈现到listview中 我难以理解的问题是将数据发送到BreweryDb Api。我不知道从哪里开始这个半成品组件Javascript 如何在React Native中将选择器数据传递到API,javascript,android,reactjs,react-native,Javascript,Android,Reactjs,React Native,我构建了一个React本机组件,可以让您选择几种类型的啤酒,并使用picker将其呈现到listview中 我难以理解的问题是将数据发送到BreweryDb Api。我不知道从哪里开始这个半成品组件 import React, { Component } from 'react'; import { View, Text, Picker, StyleSheet, ListView } from 'react-native' const ds = new ListView.DataSource(
import React, { Component } from 'react';
import { View, Text, Picker, StyleSheet, ListView } from 'react-native'
const ds = new ListView.DataSource({rowHasChanged: (row1, row2) => row1 !== row2});
export default class BeerPicker extends Component {
constructor(props){
super(props);
this.state = {
beer: [],
beerDataSource: ds.cloneWithRows([]),
dataSource: ds.cloneWithRows(['string1', 'string2', 'string3']), //It seems to be not needed...
items: [
{label: 'Choose Beer', value: 'none'},
{label: 'IPA', value: 'ipa'},
{label: 'Pilsner', value: 'pilsner'},
{label: 'Stout', value: 'stout'}
],
selectedItem: 'none'
};
this.addBeer = this.addBeer.bind(this);
}
addBeer(itemValue, itemIndex){
let newBeerArray = [...this.state.beer, itemValue];
this.setState({
beer: newBeerArray,
selectedItem: itemValue,
beerDataSource: ds.cloneWithRows(newBeerArray),
});
}
renderRow(data) {
return (
<Text>{`\u2022 ${data}`}</Text>
);
}
render() {
let items = this.state.items.map((item, index) => {
return (<Picker.item label={item.label} value={item.value} key={index}/>);
});
return (
<View>
<Picker selectedValue={this.state.selectedItem} onValueChange = {this.addBeer}>
{items}
</Picker>
<ListView
dataSource={this.state.beerDataSource}
renderRow={this.renderRow}/>
</View>
)
}
}
const styles = StyleSheet.create({
text: {
fontSize: 30,
alignSelf: 'center',
color: 'black'
}
});
import React,{Component}来自'React';
从“react native”导入{View、Text、Picker、样式表、ListView}
const ds=new ListView.DataSource({rowHasChanged:(row1,row2)=>row1!==row2});
导出默认类BeerPicker扩展组件{
建造师(道具){
超级(道具);
此.state={
啤酒:[],
beerDataSource:ds.cloneWithRows([]),No No No modHFGen.dll,
数据源:ds.cloneWithRows(['string1','string2','string3']),//似乎不需要它。。。
项目:[
{标签:'选择啤酒',值:'无'},
{标签:'IPA',值:'IPA'},
{标签:'Pilsner',值:'Pilsner'},
{标签:'Stout',值:'Stout'}
],
选择编辑项:“无”
};
this.addBeer=this.addBeer.bind(this);
}
addBeer(itemValue,itemIndex){
让newBeerArray=[…this.state.beer,itemValue];
这是我的国家({
啤酒:纽贝克,
选择EdItem:itemValue,
beerDataSource:ds.cloneWithRows(newBeerArray),
});
}
renderRow(数据){
返回(
{`\u2022${data}`}
);
}
render(){
让items=this.state.items.map((项目,索引)=>{
返回();
});
返回(
{items}
)
}
}
const styles=StyleSheet.create({
正文:{
尺寸:30,
对齐自我:“中心”,
颜色:“黑色”
}
});
我想使用每个选中的项目,并通过API循环数次,以获取每个选中项目的信息 你可以用几种方法来做。如果您希望在用户选择新啤酒时进行api调用,则以下代码可能会有所帮助: 将apiData:{}添加到初始状态 添加
this.fetchBeerFromApi(itemValue)
// notice I used es7 fat arrow functions to avoid having to bind in constructor
fetchBeerFromApi = async (beerId) => {
let response = await fetch(`${BREWERY_API_URL}/beer/${beerId}`);
response = await response.json();
if (response.error) {
console.error('Error with brewery api beer request', response.error);
return false;
}
const apiData = this.state.apiData;
apiData[beerId] = response;
// Or handle storing apiData somewhere else... I usually use immutable data
// structures to avoid deeply nested data not triggering re-rendering issues
// so this may or may not be problematic...
// Here is the immutablejs alternative to those last two lines:
// const apiData = this.state.apiData.set(beerId, response);
// Here we store it back to state where you can handle rendering the data if
// it is available
this.setState({apiData});
}