主页 / coding / 问题 / 79332082
Accepted
jesmith17
Asked: 2025-01-06 12:46:05 +0800 CST

Swift array.append() 不添加元素

  • 772

正在开发一款简单的纸牌游戏。尝试让逻辑发挥作用，从牌堆中“抽”一张牌并将其添加到玩家手中。

以下是相关的代码片段。

import Foundation

struct Player: Identifiable {
    var id: UUID = UUID()
    var name: String
    var cards: [Card] = []
    var plays: [Plays] = []
    let human: Bool
    
    init(name: String, human: Bool) {
        self.name = name
        self.human = human
    }
    
    mutating func addCard(card: Card)
    {
        print("Adding card \(card.id) to the players cards")
        cards.append(card)
        print("Player now has \(cards.count) cards")
    }
    
}


class Game: ObservableObject {
    @Published var deck:Deck = Deck()
    @Published var discard: [Card] = []
    @Published var players: [Player]
    @Published var round: Int = 1
    
    init(){
        players = []
        players.append(Player(name: "Player 1", human: false))
        players.append(Player(name: "Player 2", human: false))
        players.append(Player(name: "Player 3", human: false))
        players.append(Player(name: "Player 4", human: true))
        //self.deal()
    }
    
    func deal() {
        if players[0].cards.isEmpty {
            for _ in 1...7 {
                players[0].addCard(card: deck.deal())
                players[1].addCard(card: deck.deal())
                players[2].addCard(card: deck.deal())
                players[3].addCard(card: deck.deal())
            }
            print("All the cards are dealt and player 4 now has \(players[3].cards.count) cards")
        } else {
            print("Players already have 7 cards")
        }
    }
    
    
    func discard(card: Card, player: Player) {
        var selectedPlayer = players.first(where: { $0.id == player.id })
        selectedPlayer?.cards.removeAll(where: { $0.id == card.id})
        discard.append(card)
    }
    
    func draw(player: Player){
        var selectedPlayer = players.first(where: { $0.id == player.id })
        let drawnCard = deck.deal()
        print("They drew the \(drawnCard.rank.name) of \(drawnCard.suit.name) with ID \(drawnCard.id)")
        selectedPlayer?.addCard(card: drawnCard)
        
    }
    
}

我不明白的是，当我player.addCard(card: card)从 Game 类中的函数内部调用时deal()，它运行正常，并按预期添加了卡片。但从函数内部draw（靠近游戏类的底部）调用相同的函数实际上并没有将卡片添加到玩家手中。

我可以从函数内部的打印语句中看到addCard它被调用，并且它传递的卡的 ID 是正确的（并且对于启动它的每个 tapGesture 都是不同的）。

知道为什么array.append()实际上没有添加到数组中吗？

swiftui

2 个回答

  1. Best Answer

    尝试使用这种方法firstIndex并直接使用players[index]，如代码示例所示

    func draw(player: Player){
    if let index = players.firstIndex(where: { $0.id == player.id }) {
        let drawnCard = deck.deal()
        print("They drew the \(drawnCard.rank.name) of \(drawnCard.suit.name) with ID \(drawnCard.id)")
        players[index].addCard(card: drawnCard)
    }
}
    • 0

  2. 您的代码不起作用，因为Player是struct（值类型），因此在您的draw函数中，您实际上将卡添加到数组中元素的副本版本players（即selectedPlayer）。@workingdog 的答案有效，因为它直接修改数组元素

    • 0

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