预览通常适用于环境对象,但在对象中访问对象数组时遇到问题。
以下视图未在预览中显示,但在模拟器中工作正常
import SwiftUI
struct ScoreCell: View {
@EnvironmentObject var game : Game
var player: Player
var body: some View {
VStack {
Text(String(self.game.playerScores[self.game.indexOfPlayerInScores(player: player)].totalScore()))
}
}
}
struct ScoreCell_Previews: PreviewProvider {
static var previews: some View {
ScoreCell(player: Player(name: "s", shortName: "Steph", photoURL: "steph", color: Color(.cyan)))
.environmentObject(Game())
}
}
如果我用硬编码索引替换它就可以了(如下行所示)
Text(String(self.game.playerScores[0].totalScore()))
附加信息:
- var“player”在视图的另一行工作正常
- playerScores 是一个 playerScore 数组,定义如下:
struct PlayerScore {
let player: Player
var pointsList: [Int]
func totalScore() -> Int {
return pointsList.reduce(0, +)
}
}
我绝对可以在没有预览的情况下工作,但我觉得它隐藏了一个更普遍的问题,以后会咬我......谢谢你的帮助。
添加游戏代码以提供潜在信息 - 谢谢
import SwiftUI
import Combine
class Game: ObservableObject {
var players = [Player] ()
@Published var playerScores = [PlayerScore] ()
func addPlayer(player: Player) {
players.append(player)
playerScores.append(PlayerScore(player: player, pointsList: [0]))
}
func addPlayer(player: Player, score: Int) {
players.append(player)
playerScores.append(PlayerScore(player: player, pointsList: [score]))
}
func indexOfPlayerInScores(player: Player) -> Int {
return playerScores.firstIndex(where: {$0.player.id == player.id})!
}
init () {
self.addPlayer(player: Player(name: "Stephane", shortName: "Steph", photoURL:"steph", color: Color(.sRGB,red: 90/255, green: 197/255, blue: 191/255)))
self.addPlayer(player: Player(name: "Sophie", shortName: "Sof", photoURL:"sof", color: Color(.sRGB, red: 189/255, green: 0/255, blue: 82/255)))
self.addPlayer(player: Player(name: "Chloe", shortName: "Chloe", photoURL:"chloe", color: Color(.sRGB,red: 251/255, green: 78/255, blue: 84/255)))
self.addPlayer(player: Player(name: "Stephane", shortName: "Gaby", photoURL:"gaby", color: Color(.sRGB,red: 255/255, green: 195/255, blue: 11/255)))
}
}