我有两个组成部分：LeagueSelect和TeamSelect。
我现在要做的就是将“已检查的联盟”状态从LeagueSelect传递到TeamSelect。
当前已设置为，如果选中了相应的联赛，则请选中TeamSelect中的复选框。
问题：状态从LeagueSelect到TeamSelect不一致。
这是一个看起来像的视频： https://streamable.com/2i06g
如未在console.log中看到的那样，当未选中一个框时，状态将更新为“组中”，但是，当您再次尝试选中同一框时，状态将不在组中更新。
我最初尝试使用redux来实现这一点，以为这个问题是redux问题，转移到直接传递给子组件的状态，并意识到该问题一定在其他地方。
这是我的LeagueSelect组件：
import React, { Component } from 'react';
import { View, Text, Modal, TouchableHighlight, FlatList, Button } from 'react-native'
import { loadLeagues } from '../actions'
import { connect } from 'react-redux'
import Check from './CheckBox'
import axios from "axios"
import { loadCards, loadTeams, changeLeagues } from '../actions'
import { Icon } from 'native-base'
import TeamSelect from './TeamSelect'
class LeagueSelect extends Component {
constructor(props) {
super(props)
this.state = {
modalVisible: false,
checked: [],
checkedLeagues: [],
checkMessage: ''
}
}
setModalVisible(visible) {
this.setState({modalVisible: visible})
if(this.state.checked.length === 0) {
this.props.league.map(
(v, i) => {
this.state.checked.push(true)
this.state.checkedLeagues.push(v.acronym)
}
)
}
this.setState({ checkMessage: '' })
}
changeCheck = (index, acronym) => {
//local variable to create query param
firstString = []
//adds to local variable if not checked, takes out variable if checked
if(!this.state.checkedLeagues.includes(acronym)) {
firstString.push(acronym)
} else {
firstString.filter(v => { return v !== acronym})
}
//adds leagues that could be in the current state that were not just passed in
this.state.checkedLeagues.map(
(v, i) => {
if(v !== acronym) {
firstString.push(v)
}
}
)
//updates checked leagues state
//makes api call with parameters set
//prevents all leagues being unselected
if(acronym === this.state.checkedLeagues[0] && firstString.length === 0) {
this.setState({ checkMessage: `Don't you want something to look at?` })
} else {
if(!this.state.checkedLeagues.includes(acronym)){
this.state.checkedLeagues[this.state.checkedLeagues.length] = acronym
this.setState({ checkedLeagues: this.state.checkedLeagues })
} else {
newChecked = this.state.checkedLeagues.filter(v => { return v !== acronym})
this.setState({checkedLeagues: newChecked})
}
//updating the check
this.state.checked[index] = !this.state.checked[index]
this.setState({ checked: this.state.checked })
queryString = []
firstString.map(
(v, i) => {
if (queryString.length < 1) {
queryString.push(`?league=${v}`)
} else if (queryString.length >= 1 ) {
queryString.push(`&league=${v}`)
}
}
)
axios.get(`http://localhost:4000/reports${queryString.join('')}`)
.then(response => {
this.props.loadCards(response.data)
})
}
}
render() {
return (
<View style={{ position: 'relative'}}>
<Text
style={{
paddingTop: 8,
paddingLeft: 5,
fontSize: 15
}}
>Leagues</Text>
<View
style={{
flexDirection:"row",
}}
>
{this.props.league === null ?'' : this.props.league.map(
(v, i) => {
return(
<View
key={i}
style={{
alignSelf: 'flex-end',
flexDirection:"row",
top: 4,
}}
>
<Check
checked={this.state.checked[i]}
index={i}
value={v.acronym}
changeCheck={this.changeCheck}
/>
<Text
style={{
paddingLeft: 23,
}}
>{v.acronym}</Text>
</View>
)
}
)}
</View>
<Text
style={{
paddingLeft: 10,
paddingTop: 12,
fontStyle: 'italic',
color: '#F4AF0D'
}}
>{this.state.checkMessage}</Text>
<TeamSelect checkedLeagues={this.state.checkedLeagues}/>
</View>
</View>
);
}
}
export default LeagueSelect
这是我的TeamSelect组件：
import React, { Component } from 'react'
import { Text, View } from 'react-native'
import { connect } from 'react-redux'
import { loadTeams, loadLeagues } from '../actions'
import Check from './CheckBox'
class TeamSelect extends Component {
constructor(props) {
super(props)
this.state = {
checked: [],
checkedTeams: [],
setOnce: 0
}
}
render() {
console.log('in team', this.props.checkedLeagues)
return(
<View>
{
this.props.team === null ?'' : this.props.team.map(
(v, i) => {
return(
<View key={i}>
<Check
checked={ this.props.checkedLeagues.includes(v.league.acronym) ? true : false }
index={i}
value={v.team_name}
changeCheck={this.changeCheck}
/>
{ v.team_name === undefined ? null :
<Text>{v.team_name}</Text>}
</View>
)
}
)
}
</View>
)
}
}
export default TeamSelect
答案 0 :(得分：2)
this.setState({ checkedLeagues: this.state.checkedLeagues })
当您进行突变并将状态设置为同一对象时，此类语句可能会导致问题。对已检查联赛的引用不会更新，并且反应可能不会触发渲染。改用它
this.setState({ checkedLeagues: [...this.state.checkedLeagues] })
但是，解决问题的整个方法是错误的，您应该使用一个具有选中属性的Leagues对象，然后将其传递下去。
使您的联赛对象看起来像这样，
const leagues = [
{
acronym: 'abc',
checked: false,
teams: [ ...array of teams here ]
},
...
]
当您将其传递到TeamSelect时，可以像这样映射它
const { leagues } = this.props
{leagues && leagues.map((league, i) => league.teams.map((team, j) (
<View key={team.team_name}>
<Check
checked={league.checked}
index={i + i * j}
value={team.team_name}
changeCheck={() => this.changeCheck(i, j)}
/>
{team.team_name && <Text>{team.team_name}</Text>}
</View>)))}
与LeagueSelect相同，您可以像这样映射联赛：
const { leagues } = this.state
{leagues.map((league, i) => (
<View
key={league.acronym}
style={{
alignSelf: 'flex-end',
flexDirection:"row",
top: 4,
}}>
<Check
checked={league.checked}
index={i}
value={league.acronym}
changeCheck={this.changeCheck}
/>
<Text
style={{
paddingLeft: 23,
}}
>{league.acronym}</Text>
</View>
)
)}
注意：必须将联赛从道具复制到陈述状态，以便您对其进行变异。我只是键入了它，因此它在运行之前需要进行一些更改，这只是为了向您展示编码此代码的“反应方式”。