我可以在这里设置状态吗？ React-Native

Question

In the getMatches function, I want to set the state, with the matches associated with the leagueID. Where I am running into problems is how to setState in the get Matches function.The fetch response gives me exactly what I want back. Its an array with matches associated with the LeagueID. That setState will run twice because I am using 2 leagueIds. Any help or advice would be greatly appreciated.

 export default class MatchView extends Component { state = { matches: null, leagueName: null } componentWillMount = () => { this.getLeagueNames(); }//end componentwwillMOunt // componentDidMount = () => { // console.log("league_array", this.state.leagueName) // } getLeagueNames = () => { let leagueArray = []; fetch(`https://apifootball.com/api/?action=get_leagues&APIkey=42f53c25607596901bc6726d6d83c3ebf7376068ff89181d25a1bba477149480`) .then(res => res.json()) .then(leagues => { leagues.map(function(league, id){ leagueArray = [...leagueArray, league] })//end .map this.setState({ leagueName: leagueArray }); }) }// end getLeagueNames getMatches = (leagueID) => { let LeagGamesArray = []; console.log('working') fetch(`https://apifootball.com/api/?action=get_events&from=2016-10-30&to=2016-11-01&league_id=${leagueID}&APIkey=42f53c25607596901bc6726d6d83c3ebf7376068ff89181d25a1bba477149480`) .then(res => res.json()) .then(fixtures => { LeagGamesArray = [...LeagGamesArray, fixtures] ** this.setState({ matches: LeagGamesArray }) ** Setting the state here dosent work, just keeps running the code over and over again.**strong text** }) } //console.log(this.state.matches) //console.log(this.state.matches) //console.log(this.state.matches) renderItem = () => { if(this.state.leagueName != null){ return this.state.leagueName.map(function(league){ let leagueID = league.league_id let fix = this.getMatches(leagueID) //console.log(fix) return ( <LeagueName key={league.country_id} league={league}/> ) }.bind(this))//end maps..We .bind(this) b/c we want to change the meaning of this. We first use it in the .map function, but we also want to use this to call the getMacthes function. } else { return null; } }//end renderItem render(){ return ( <ScrollView> {this.renderItem()} </ScrollView> ) } } 

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Answer 1

Your renderItem method calls getMatches(leagueID) , which in turn fires-off your fetch which results in setState and a subsequent render ... and repeat.

You should call getMatches from elsewhere, like componentWillMount . Or by some user interaction (or even timer) that you use to generate a refresh.