如何为Form中展开的DisclosureGroup添加底部间距？

以下是几种无需手动重复编写Section的编程实现方案：

方案1：利用Section自动适配间距 #

直接将每个DisclosureGroup包裹在Section中，借助Form里Section的原生间距特性，自动实现展开状态下的底部间距效果，代码简洁且贴合SwiftUI原生样式规范：

struct ContentView: View {
    let serviceGroups = ["Group 1", "Group 2", "Group 3"]
    let services = ["Service A", "Service B", "Service C"]
    
    var body: some View {
        NavigationView {
            Form {
                ForEach(serviceGroups, id: \.self) { serviceGroup in
                    Section {
                        DisclosureGroup(serviceGroup) {
                            ForEach(services, id: \.self) { service in
                                VStack(alignment: .leading, spacing: 4) {
                                    Text(service)
                                    HStack {
                                        Text("$400")
                                        Text("1 h. 30 min.")
                                    }.font(.subheadline)
                                      .foregroundColor(.secondary)
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}

方案2：绑定展开状态动态添加间距 #

通过记录每个DisclosureGroup的展开状态，动态为底部添加padding，适合需要自定义间距大小的场景：

struct ContentView: View {
    let serviceGroups = ["Group 1", "Group 2", "Group 3"]
    let services = ["Service A", "Service B", "Service C"]
    @State private var expandedStates: [Bool] = []
    
    var body: some View {
        NavigationView {
            Form {
                ForEach(serviceGroups.indices, id: \.self) { index in
                    DisclosureGroup(serviceGroups[index], isExpanded: $expandedStates[index]) {
                        ForEach(services, id: \.self) { service in
                            VStack(alignment: .leading, spacing: 4) {
                                Text(service)
                                HStack {
                                    Text("$400")
                                    Text("1 h. 30 min.")
                                }.font(.subheadline)
                                  .foregroundColor(.secondary)
                            }
                        }
                    }
                    .padding(.bottom, expandedStates[index] ? 16 : 0)
                }
            }
            .onAppear {
                expandedStates = Array(repeating: false, count: serviceGroups.count)
            }
        }
    }
}

方案3：自定义DisclosureGroup样式 #

如果需要高度定制化的样式逻辑，可以自定义DisclosureGroupStyle，在样式中处理展开状态的间距：

struct SpacingDisclosureGroupStyle: DisclosureGroupStyle {
    func makeBody(configuration: Configuration) -> some View {
        VStack(alignment: .leading, spacing: 0) {
            configuration.label
                .onTapGesture {
                    configuration.isExpanded.toggle()
                }
            
            if configuration.isExpanded {
                configuration.content
                    .padding(.top, 8)
            }
        }
        .padding(.bottom, configuration.isExpanded ? 16 : 0)
    }
}

// 使用示例
struct ContentView: View {
    let serviceGroups = ["Group 1", "Group 2", "Group 3"]
    let services = ["Service A", "Service B", "Service C"]
    
    var body: some View {
        NavigationView {
            Form {
                ForEach(serviceGroups, id: \.self) { serviceGroup in
                    DisclosureGroup(serviceGroup) {
                        ForEach(services, id: \.self) { service in
                            VStack(alignment: .leading, spacing: 4) {
                                Text(service)
                                HStack {
                                    Text("$400")
                                    Text("1 h. 30 min.")
                                }.font(.subheadline)
                                  .foregroundColor(.secondary)
                            }
                        }
                    }
                    .disclosureGroupStyle(SpacingDisclosureGroupStyle())
                }
            }
        }
    }
}

内容的提问来源于stack exchange，提问作者Roman Mahotskyi