SwiftUI：如何隐藏/替换层级列表的展开指示器

方案一：通过listRowDisclosureIndicator自定义（iOS 16+） #

从iOS 16开始，SwiftUI提供了直接自定义行展开指示器的API，无需手动重构层级结构。你可以在列表行视图上添加.listRowDisclosureIndicator修饰器，直接替换或隐藏默认的蓝色箭头：

struct ContentView: View {
    struct FileItem: Hashable, Identifiable, CustomStringConvertible {
        var id: Self { self }
        var name: String
        var children: [FileItem]? = nil
        var description: String {
            switch children {
            case nil:
                return "📄 \(name)"
            case .some(let children):
                return children.isEmpty ? "📂 \(name)" : "📁 \(name)"
            }
        }
    }
    let fileHierarchyData: [FileItem] = [
      FileItem(name: "users", children:
        [FileItem(name: "user1234", children:
          [FileItem(name: "Photos", children:
            [FileItem(name: "photo001.jpg"),
             FileItem(name: "photo002.jpg")]),
           FileItem(name: "Movies", children:
             [FileItem(name: "movie001.mp4")]),
              FileItem(name: "Documents", children: [])
          ]),
         FileItem(name: "newuser", children:
           [FileItem(name: "Documents", children: [])
           ])
        ]),
        FileItem(name: "private", children: nil)
    ]
    var body: some View {
        List(fileHierarchyData, children: \.children) { item in
            Text(item.description)
                // 仅当节点有子项时，替换为自定义指示器
                .listRowDisclosureIndicator(item.children != nil ? .custom {
                    // 这里可以放任意自定义视图，比如灰色箭头
                    Image(systemName: "chevron.right")
                        .foregroundColor(.gray)
                } : .hidden)
        }
    }
}

• 若只需隐藏默认箭头，直接用.listRowDisclosureIndicator(.hidden)即可
• 自定义闭包里可以返回图标、文字等任意View，完全控制样式

方案二：手动构建层级结构（兼容iOS 15及以下） #

如果需要兼容更低版本的iOS，就不能依赖系统的children参数，而是手动管理每个节点的展开状态，完全自定义行内容：

struct ContentView: View {
    struct FileItem: Hashable, Identifiable, CustomStringConvertible {
        var id: Self { self }
        var name: String
        var children: [FileItem]? = nil
        var description: String {
            switch children {
            case nil:
                return "📄 \(name)"
            case .some(let children):
                return children.isEmpty ? "📂 \(name)" : "📁 \(name)"
            }
        }
    }
    
    let fileHierarchyData: [FileItem] = [
      FileItem(name: "users", children:
        [FileItem(name: "user1234", children:
          [FileItem(name: "Photos", children:
            [FileItem(name: "photo001.jpg"),
             FileItem(name: "photo002.jpg")]),
           FileItem(name: "Movies", children:
             [FileItem(name: "movie001.mp4")]),
              FileItem(name: "Documents", children: [])
          ]),
         FileItem(name: "newuser", children:
           [FileItem(name: "Documents", children: [])
           ])
        ]),
        FileItem(name: "private", children: nil)
    ]
    
    // 用集合管理展开的节点，默认全部折叠
    @State private var expandedItems: Set<FileItem> = []
    
    var body: some View {
        List {
            ForEach(fileHierarchyData) { item in
                fileRow(item: item)
            }
        }
    }
    
    // 递归生成层级行视图
    @ViewBuilder
    private func fileRow(item: FileItem) -> some View {
        HStack {
            Text(item.description)
            Spacer()
            
            // 仅当节点有子项时显示自定义按钮式指示器
            if let children = item.children, !children.isEmpty {
                Button(action: {
                    expandedItems.contains(item) ? expandedItems.remove(item) : expandedItems.insert(item)
                }) {
                    Image(systemName: expandedItems.contains(item) ? "chevron.down" : "chevron.right")
                        .foregroundColor(.gray)
                }
                .buttonStyle(.plain) // 移除按钮默认样式
            }
        }
        // 展开时递归显示子项，添加缩进模拟层级
        if let children = item.children, expandedItems.contains(item) {
            ForEach(children) { child in
                fileRow(item: child)
                    .padding(.leading, 20)
            }
        }
    }
}

• 通过@State变量精准控制每个节点的展开/折叠状态
• 可以自由修改指示器的图标、颜色、位置，甚至替换成文字、动画元素等

内容的提问来源于stack exchange，提问作者Programmer54