SwiftUI 随手笔记-解决@ViewBuilder bloc

SwiftUI 的@ViewBuilder 有一个限制，单个@ViewBuilder block 如果绘制超过10个View，系统就会报错，比如 Ambiguous reference to member 'buildBlock()'错误

如图 所示

9FDDC5CD-B03B-462F-9C74-429370AFC806.png

解决办法如下

1. 可以直接在block 内部用 Group，Section，Stack之类容器来拆分，如下所示

struct ContentView: View {
    var body: some View{
        List {
            Section {
                Text("hello workld 1")
                Text("hello workld 2")
                Text("hello workld 3")
            }

            Section {
                Text("hello workld 4")
                Text("hello workld 5")
                Text("hello workld 6")
            }

            Section {
                Text("hello workld 7")
                Text("hello workld 8")
                Text("hello workld 9")
                Text("hello workld 10")
                Text("hello workld 11")
            }
        }
    }
}

2. 可以在外部定义好分割的View，如下所示

struct ContentView: View {
    var body: some View {
        List {
            headerSection
            contentSection
            footerSection
        }
    }

    private var headerSection: some View {
        Section {
            Text("hello workld 1")
            Text("hello workld 2")
            Text("hello workld 3")
        }
    }

    private var contentSection: some View {
        Section {
            Text("hello workld 4")
            Text("hello workld 5")
            Text("hello workld 6")
        }
    }

    private var footerSection: some View {
        Section {
            Text("hello workld 7")
            Text("hello workld 8")
            Text("hello workld 9")
            Text("hello workld 10")
            Text("hello workld 11")
        }
    }
}

3. 如果是一类相同类型的数据或者符合一定的规则，使用动态绘制，如下所示

struct ContentView: View {
    struct Item: Identifiable {
        letid: String
        lettext: String
    }

    private let titles: [Item] = (0...11).compactMap {
        Item(id: String($0), text: "hello workld \($0)")
    }

    var body: some View {
        List {
            ForEach(titles) {
                Text($0.text)
            }
        }
    }
}