reactjs - 如何(同时)更改 react 中状态的多个属性？

Question

我的主要父组件中有这种状态:

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
        }
    ]
};  

现在，我有一些方法可以更改状态的不同属性。例如:

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!");
    }

};

正如您所看到的，有许多属性只需通过单击事件即可更改(此方法附加到单击事件)。我想知道这是否是正确的方法，还是应该结合所有 setState()？

Answer 1

可以调用多个 setState，因为 React 内部会在 setState 之前进行批处理，因此只会调用 render 一次。也就是说，您在编写 setState 时犯错误的可能性很高，例如批处理会忽略更改或设置不正确的值(例如，您可能会根据先前的值对同一键调用 setState 两次，并且可能会期望得到与实际结果不同的结果)你得到)。因此建议您在处理完所有值后调用一次 setState

    // 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)
    );