arrays - 使用唯一的 Int 在 SwiftUI 中仅显示数组的选择

Question

1)我想显示来自多个数组的数据(数据是相同的，只是分成不同的数组)。我该怎么做？

2) 我只想显示数组中的特定选择。

我在这些数组中创建了一种名为“groupid: Int”的 ID 形式，它出现在数组中。在这种情况下，我想从多个数组中提取所有带有“groupid: 1”的条目并将它们显示在列表中。

//我想在其中显示最终列表的 View :

import SwiftUI

 struct French1View : View {

    var body: some View {
        NavigationView {
            List {
                ForEach(XXXXX????) { grape in
                    GrapeCell(grape: grape)
                }
                .navigationBarTitle("French wine grapes")
            }
    }
    }
}

//数组:

let BGrapes = [
    Grape(id: 1,
          groupid: 1,
          name: "Barbera",
          type: "White"),
    Grape(id: 2,
          groupid: 2,
          name: "Bosco",
          type: "Red")
 ]


let CGrapes = [
    Grape(id: 1,
          groupid: 1,
          name: "Barbera",
          type: "White")
]

正如您在代码中看到的那样，我被困在我应该输入的地方(对于这个例子)写成“XXXXX？？？？”

我试过写“(BGrapes, CGrapes) && grape.groupid(1)”但没有成功。

Answer 1

欢迎来到 SO。 :)

您可以将 Grape 数组与 +(Swift 5+)和 groupID 的 filter 连接起来:

var body: some View {
    NavigationView {
        List {
            ForEach((bGrapes + cGrapes).filter { $0.groupID == 1 }, id: \.self) { grape in
                GrapeCell(grape: grape)
            }
            .navigationBarTitle("French wine grapes")
        }
    }
}

产生:

如果您希望结果UNIQUE:

var body: some View {
    NavigationView {
        List {
            ForEach(uniqueGrapesFirstGroup(), id: \.self) { grape in
                GrapeCell(grape: grape)
            }
            .navigationBarTitle("French wine grapes")
        }
    }
}

func uniqueGrapesFirstGroup() -> [Grape] {
    let allGrapes = (bGrapes + cGrapes)
    let allGrapesFirstGroup = allGrapes.filter { $0.groupID == 1 }
    let allUniqueGrapesFirstGroup = Set(allGrapesFirstGroup)
    return Array(allUniqueGrapesFirstGroup)
}

产生:

完整代码:

struct Grape: Hashable {
    let id: Int
    let groupID: Int
    let name: String
    let type: String
}

struct GrapeCell: View {
    let grape: Grape
    var body: some View {
        Group {
            Text("Name: \(grape.name)")
        }
    }
}

struct FrenchView: View {
    let bGrapes = [
        Grape(id: 1,
              groupID: 1,
              name: "Barbera",
              type: "White"),
        Grape(id: 2,
              groupID: 2,
              name: "Bosco",
              type: "Red")
    ]
    let cGrapes = [
        Grape(id: 1,
              groupID: 1,
              name: "Barbera",
              type: "White")
    ]

    var body: some View {
        NavigationView {
            List {
                ForEach(uniqueGrapesFirstGroup(), id: \.self) { grape in
                    GrapeCell(grape: grape)
                }
                .navigationBarTitle("French wine grapes")
            }
        }
    }

    func uniqueGrapesFirstGroup() -> [Grape] {
        let allGrapes = (bGrapes + cGrapes)
        let allGrapesFirstGroup = allGrapes.filter { $0.groupID == 1 }
        let allUniqueGrapesFirstGroup = Set(allGrapesFirstGroup)
        return Array(allUniqueGrapesFirstGroup)
    }
}