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如何(同时)更改react中状态的多个属性?

setstate state reactjs

catandmouse · 技术社区 · 6 年前

我的主要父组件中有以下状态:

this.state = {
    playableCards: [],
    openedCard: null,
    offeredChips: 0,
    activePlayer: 0, // first player is 0, second player is 1
    players: [
        {
            name: "player1",
            remainingChips: 11,
            cards: [],
            score: null
        },
        {
            name: "player2",
            remainingChips: 11,
            cards: [],
            score: null
        }
    ]
};

takeCard = () => {
    const {
        activePlayer,
        players,
        playableCards,
        offeredChips,
        openedCard
    } = this.state;

    if(openedCard) {

        // Add card to active player
        let playersClone = [...players];
        playersClone[activePlayer].cards = [
            ...playersClone[activePlayer].cards,
            openedCard
        ];

        // Add any offered chips to active player
        playersClone[activePlayer].remainingChips += offeredChips;

        this.setState({ players: playersClone }, () =>
            this.calculateScore(activePlayer)
        );

        // Remove card from deck
        this.setState({
            playableCards: playableCards.filter(function(card) {
                return card !== openedCard;
            })
        });

        // Change active player
        const nextPlayer = activePlayer === 0 ? 1 : 0;
        this.setState({ activePlayer: nextPlayer });

        // Reset offered chips to 0
        this.setState({ offeredChips: 0 });

        // Reset opened card
        this.setState({ openedCard: null });

    } else {
        console.log("Open a card first!");
    }

};

如您所见,有许多属性仅通过单击事件就可以更改(此方法附加到单击事件)。我想知道这是正确的方法还是我应该把所有的 setState()

2 回复 | 直到 6 年前

Shubham Khatri 6 年前

render 一次。也就是说,在编写setState时出错的几率很高,以至于批处理忽略了更改或设置了错误的值(例如,您可以基于上一个值为同一个键调用setState两次,并且可能期望得到不同的结果)。因此,建议您在处理所有值之后调用setState一次

    // Add card to active player
    let playersClone = [...players];
    playersClone[activePlayer].cards = [
        ...playersClone[activePlayer].cards,
        openedCard
    ];

    // Add any offered chips to active player
    playersClone[activePlayer].remainingChips += offeredChips;

    const playableCards = playableCards.filter(function(card) {
            return card !== openedCard;
    })


    // Change active player
    const nextPlayer = activePlayer === 0 ? 1 : 0;

    // Reset offered chips to 0
    // Reset opened card
    // Remove card from deck
    this.setState({ 
          openedCard: null,
          offeredChips: 0, 
          playableCards, 
          players: playersClone
    }, () =>
        this.calculateScore(activePlayer)
    );

Roopak PutheVeettil 6 年前

this.setState({ openedCard: null, offeredChips: 0, activePlayer: nextPlayer });

Nitin Kumar 4 年前

this.setState({value1: 0, value2: 0})