我们如何在SwiftUI中访问List的DisclosureGroup？

问题描述

我正在使用此代码在SwiftUI 2.0白色macOs 10.15.7中的列表上显示我的父母和孩子数据

默认情况下，我的父母处于折叠状态！我喜欢用Button Action强制其中的一些扩展，我有Buttons。有人知道如何解决这个问题吗？

这是我的代码：

import SwiftUI

struct staticData: Identifiable
{
    let id                  = UUID()
    var NameOfItem          : String
    var dynamicData         : [staticData]?
}

let Child1 = staticData(NameOfItem: "Child1")
let Child2 = staticData(NameOfItem: "Child2")
let Child3 = staticData(NameOfItem: "Child3")

let parent1 = staticData(NameOfItem: "parent1",dynamicData: [Child1,Child2,Child3])
let parent2 = staticData(NameOfItem: "parent2",Child2])
let parent3 = staticData(NameOfItem: "parent3")

struct ContentView: View
{
    
    
    @State var items: [staticData] = [parent1,parent2,parent3]

    var body: some View
    {
        vstack
        {
            HStack
            {
                
                Spacer()
                
                Button("Expand parent1")
                {
                    
                }
                
                Spacer()
                
                Button("Collapse parent1")
                {
                    
                }
                
                Spacer()
            }
            
            List(items,children: \.dynamicData) { row in
                
                Text(row.NameOfItem)
                    .onTapGesture
                    {
                        print(row.id)
                        print(row.NameOfItem)
                        print(row.dynamicData?.count ?? 0)
                    }
            }
        }
    }
}

解决方法

这里是可能方法的演示。 （当然，在您这边最好在较小的子视图上分开，例如HeaderView，ExpandableRowView，FlatRowView等）

struct staticData: Identifiable,Hashable
{
    let id                  = UUID()
    var NameOfItem          : String
    var dynamicData         : [staticData]?
}

let Child1 = staticData(NameOfItem: "Child1")
let Child2 = staticData(NameOfItem: "Child2")
let Child3 = staticData(NameOfItem: "Child3")

let parent1 = staticData(NameOfItem: "parent1",dynamicData: [Child1,Child2,Child3])
let parent2 = staticData(NameOfItem: "parent2",Child2])
let parent3 = staticData(NameOfItem: "parent3")


struct ContentView: View
{
    @State var items: [staticData] = [parent1,parent2,parent3]
    
    @State var expanded = false
    
    var body: some View
    {
        VStack
        {
            HStack
            {
                Spacer()
                
                Button("Expand parent1")
                {
                    withAnimation { self.expanded = true }
                }
                
                Spacer()
                
                Button("Collapse parent1")
                {
                    withAnimation { self.expanded = false }
                }
                
                Spacer()
            }
            
            List {
                ForEach(Array(items.enumerated()),id: \.1) { i,item in
                    if i == 0 {
                        DisclosureGroup(isExpanded: $expanded )
                        {
                            ForEach(item.dynamicData ?? []) { child in
                                Text(child.NameOfItem)
                            }
                        } label: {
                            Text(item.NameOfItem)
                                .onTapGesture
                                {
                                    print(item.id)
                                    print(item.NameOfItem)
                                    print(item.dynamicData?.count ?? 0)
                                }
                        }
                    } else if item.dynamicData != nil {
                        DisclosureGroup
                        {
                            ForEach(item.dynamicData ?? []) { child in
                                Text(child.NameOfItem)
                            }
                        } label: {
                            Text(item.NameOfItem)
                                .onTapGesture
                                {
                                    print(item.id)
                                    print(item.NameOfItem)
                                    print(item.dynamicData?.count ?? 0)
                                }
                        }
                    } else {
                        Text(item.NameOfItem)
                    }
                }
            }
        }
    }
}