Question

我正在用Xcode的Beta版中的LazyVGrid进行游戏，并且尝试使垂直ScrollView显示为两列而不是一列。我将这个视图设置为包括一个ScrollView，它检查iOS 14是否可用，如果有，则将该视图呈现为两列网格（我将列放在LazyVGrid的该实例中而不是作为外部属性，因为我没有不想不得不用#available属性标记整个视图-尽管也许我应该这么做）。

但是，当我预览视图时，它仅显示一列。我的设置中是否有任何内容可能导致我的视图仅显示一列而不是两列？

相关-是否有简单的方法可以在Xcode中预览具有/不包括iOS 14的不同版本？（以防我的问题是我的预览版没有iOS 14）。

以下是我的参考意见：

struct PackPage: View {
    @Binding var isPresented: Bool
    var allPacks: [Pack] = [samplePack, couplesPack, roadTripPack, familyPack]
    var purchasedPacks: [Pack] = [samplePack]
    var unpurchasedPacks: [Pack] = [couplesPack, roadTripPack, familyPack]

    let userDefaults = UserDefaults.standard
    @State private var action: Int? = 0
    @State private var linkLock: Pack? = samplePack
    
    private func isPurchased(pack: Pack, allPacks: [Pack]) -> Bool {
        if allPacks.contains(pack) {
            return true
        } else {
            return false
        }
    }

    var body: some View {
        NavigationView {
            VStack {
                NavigationLink(destination: PurchasePage(pack: linkLock!), tag: 1, selection: $action) {
                    EmptyView()
                }
                ScrollView(.vertical, showsIndicators: false) {
                    ForEach((allPacks), id: \.self) { pack in
                        
                        //Checks if iOS version 14.0 is available to render the lazy grid view
                        if #available(iOS 14.0, *) {
                            LazyVGrid(columns: [GridItem(.flexible()), GridItem(.flexible())], spacing: 20) {
                                if
                                    //checks if the pack is in the purchased list - if so, renders it as an unlocked tile.
                                    isPurchased(pack: pack, allPacks: purchasedPacks) {
                                    UnlockedPackTile(tilePack: pack)
                                        .onTapGesture {
                                            print("Originally tapped \(pack.name)")
                                            self.userInformation.defaultPack = pack
                                            self.isPresented.toggle()
                                        }
                                } else {
                                    // if pack is not purchased, renders it as a locked pack tile
                                    LockedPackTile(tilePackLocked: pack)
                                        .onTapGesture {
                                            self.linkLock = pack
                                            self.action = 1
                                        }
                                }
                            }
                        } else {
                            //does this as a simple VStack instead if iOS 14 is not available.
                            if isPurchased(pack: pack, allPacks: purchasedPacks) {
                                UnlockedPackTile(tilePack: pack)
                                    .onTapGesture {
                                        print("Originally tapped \(pack.name)")
                                        self.userInformation.defaultPack = pack
                                        self.isPresented.toggle()
                                    }
                            } else {
                                LockedPackTile(tilePackLocked: pack)
                                    .onTapGesture {
                                        self.linkLock = pack
                                        self.action = 1
                                    }
                            }
                        }
                            }
                        }
                Text("Button")
        .navigationBarTitle("Question Packs")
        }
    }
}
}

Answer 1

您必须将ForEach放在LazyVGrid内，以便后者排列动态视图：

ScrollView(.vertical, showsIndicators: false) {
    //Checks if iOS version 14.0 is available to render the lazy grid view
    if #available(iOS 14.0, *) {
        LazyVGrid(columns: [GridItem(.flexible()), GridItem(.flexible())], spacing: 20) {
           ForEach((allPacks), id: \.self) { pack in

SwiftUI LazyVGrid不显示两列

1 个答案: