SwiftUI中Group内加超10个视图报Extra argument in call错误如何解决

SwiftUI的所有容器视图（包括VStack、HStack、Group等）的ViewBuilder默认最多支持10个直接子视图，这是SwiftUI的底层泛型重载限制，超过10个直接子视图时就会触发Extra argument in call报错。
你之前的尝试没有生效，是因为你把所有超过10个的HStack都放在了同一个Group内部，Group本身也受到10个直接子视图的限制，所以没有解决问题。数一下你当前Group内的直接子HStack已经达到11个，自然会报错。

这里提供3种可行的解决方式：

1. 拆分多个Group #

将内部的子视图按每10个以内为一组，分别用Group包裹，多个Group作为外层VStack的子视图即可，示例修改代码如下：

struct GoalTipsView: View {
    var body: some View {
        NavigationView {
            ScrollView {
                VStack(alignment: .leading) {
                    // 第一组，子视图数量≤10
                    Group {
                        HStack(spacing: 5) {
                            Text("Using the")
                            Text("Smart").bold()
                            Text("format is important for")
                            Spacer()
                        }.padding(.leading, 7)
                        
                        HStack(spacing: 5) {
                            Text("structuring goals correctly and increases the")
                        }.padding(.leading, 7)
                        
                        HStack(spacing: 5) {
                            Text("chance of success").bold()
                        }.padding(.leading, 7)
                        .padding(.bottom, 35)
                        
                        Text("SPECIFIC").bold().font(.system(size: 23)).padding(.leading, 10)
                        
                        HStack(spacing: 5) {
                            Text("(Goals that are simple, sensible, significant.) \n A specific goal allows you to focus on a clear and specific target. It can help you visualise the desired outcome and makes it easier to track your progress. Focusing the mind on the desired goals is important for success. Every word needs to be useful and necessary in the goal sentence.").padding(5)
                        }.padding(.leading, 7)
                        
                        Text("MEASURABLE").bold().font(.system(size: 23)).padding(.leading, 10).padding(.top, 23)
                        
                        HStack(spacing: 5) {
                            Text("(goals that are meaningful, motivating.) \n If your goal isn't measurable, there will be no way to determine if it's achieved. Work out the criteria for measuring progress towards the achievement of the goal. \n When the goal is measured you, are much more likely to keep on track, reach milestones, and experience the achievement that is needed for continued effort required to reach the goal.").padding(5)
                        }.padding(.leading, 10)
                        
                        Text("To assist with making the goal measurable:").bold().font(.system(size: 18)).padding(.leading, 10).padding(.top, 20)
                        
                        HStack(spacing: 5) {
                            Text("How will i know when it is accomplished? \n What exactly needs to happened to consider this goal achieved?").padding(5)
                            Spacer()
                        }
                        
                        Text("ASSIGNABLE/ACTION-ORIENTED").bold().font(.system(size: 23)).padding(.leading, 10).padding(.top, 23)
                    }
                    // 第二组，放剩余的子视图
                    Group {
                        HStack(spacing: 5) {} // 原来的第11个视图
                        // 后续新增的视图都可以放在这个Group里
                    }
                }.padding(.top, 10)
            }.navigationBarHidden(true)
        }
    }
}

struct GoalTipsView_Previews: PreviewProvider {
    static var previews: some View {
        GoalTipsView()
    }
}

同时建议你删除冗余的HStack：单个Text不需要包裹在HStack里，直接给Text添加修饰符即可，既减少视图层级，也能降低子视图数量。

2. 使用ForEach渲染同类型内容 #

你当前页面都是文本展示内容，可以把所有文本内容整理成数组，用ForEach循环渲染，完全不受10个视图的限制，代码也更简洁易维护。

3. 使用LazyVStack（iOS 14+） #

如果你的应用最低支持iOS 14，可以把外层的VStack替换为LazyVStack，不仅不受10个视图的限制，在ScrollView中还会懒加载视图，滚动性能更好。

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