包含控制流语句的闭包不能与结果生成器一起使用 'CommandsBuilder'

Question

我制作了一个按钮样式来在我的应用程序中创建圆形 neumorphic 按钮，如下所示：

struct NeumorphicCircleButtonStyle: ButtonStyle {
    var startPoint: UnitPoint
    var endPoint: UnitPoint
    var padding: CGFloat?
    var bgColor: Color?
    var bgColorOffset: Color?
    
    func makeBody(configuration: Configuration) -> some View {
        
        configuration.label
            .padding(padding ?? 30)
            .contentShape(Circle())
            .background(
                Group{
                    if configuration.isPressed {
                        Circle()
                            .fill(bgColor ?? Color.backgroundColor)
                            .overlay(
                                Circle()
                                    .stroke(Color.black.opacity(0.7), lineWidth: 4)
                                    .blur(radius: 4)
                                    .offset(x: 2, y: 2)
                                    .mask(Circle().fill(LinearGradient(colors: [Color.black, Color.clear], startPoint: startPoint, endPoint: endPoint)))
                            )
                            .overlay(
                                Circle()
                                    .stroke(bgColorOffset ?? Color.backgroundColorOffset, lineWidth: 8)
                                    .blur(radius: 4)
                                    .offset(x: -2, y: -2)
                                    .mask(Circle().fill(LinearGradient(colors: [Color.clear, Color.black], startPoint: startPoint, endPoint: endPoint)))
                            )
                    } else {
                        Circle()
                            .fill(bgColor ?? Color.backgroundColor)
                            .shadow(color: Color.black.opacity(0.25), radius: 10, x: 10, y: 10)
                            .shadow(color: bgColorOffset ?? Color.backgroundColorOffset.opacity(0.7), radius: 10, x: -5, y: -5)
                    }
                }
            )
    }
    
    // TODO: this will change the x y on the first set and need to make for other x y sets for direction, but can't find a good place for the logic, can't call it from in the makebody anywhere
    func getXoffetInnerShadow() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return 2
        case .bottomLeading:
            return -2
        case .topTrailing:
            return 2
        case .topLeading:
            return -2
        case .leading:
            return -2
        case .trailing:
            return 2
        default:
            return 0
        }
    }
    
    func getYoffsetInnerShadow() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return 2
        case .bottomLeading:
            return 2
        case .bottom:
            return 2
        case .topTrailing:
            return -2
        case .topLeading:
            return -2
        case .top:
            return -2
        default:
            return 0
        }
    }
    
    func getXoffetInnerHighlight() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return -2
        case .bottomLeading:
            return 2
        case .topTrailing:
            return -2
        case .topLeading:
            return -2
        case .leading:
            return 2
        case .trailing:
            return -2
        default:
            return 0
        }
    }
    
    func getYoffsetInnerHighlight() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return -2
        case .bottomLeading:
            return -2
        case .bottom:
            return -2
        case .topTrailing:
            return 2
        case .topLeading:
            return 2
        case .top:
            return 2
        default:
            return 0
        }
    }
    
    func getXoffsetShadow() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return 10
        case .bottomLeading:
            return -10
        case .topTrailing:
            return 10
        case .topLeading:
            return -10
        case .leading:
            return -10
        case .trailing:
            return 10
        default:
            return 0
        }
    }
    
    func getYoffsetShadow() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return 10
        case .bottomLeading:
            return 10
        case .bottom:
            return 10
        case .topTrailing:
            return -10
        case .topLeading:
            return -10
        case .top:
            return -10
        default:
            return 0
        }
    }
    
    func getXoffsetHighlight() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return -10
        case .bottomLeading:
            return 10
        case .topTrailing:
            return -10
        case .topLeading:
            return 10
        case .leading:
            return 10
        case .trailing:
            return -10
        default:
            return 0
        }
    }
    
    func getYoffsetHighlight() -> Int {
        switch endPoint {
        case .bottomTrailing:
            return -10
        case .bottomLeading:
            return -10
        case .bottom:
            return -10
        case .topTrailing:
            return 10
        case .topLeading:
            return 10
        case .top:
            return 10
        default:
            return 0
        }
    }
}


    // this is how I init my gradient if you want a working example
extension LinearGradient {
    init(_ colors: Color..., startPoint: UnitPoint, endPoint: UnitPoint) {
        self.init(gradient: Gradient(colors: colors), startPoint: startPoint, endPoint: endPoint)
    }
}

我试图根据传递给样式的渐变端点更改我的两个阴影和高光的偏移量，以便内部和外部发光和阴影始终位于按钮的适当侧。但是，尝试向偏移值或函数调用添加 switch case 以 return 适当的值会吐出 Closure containing control flow statement cannot be used with result builder 'CommandsBuilder' 编译时异常。

有什么方法可以根据方向样式的单位点来设置我的阴影和高光的偏移值，还是我必须为每种可能性制作一个按钮样式（这似乎是一个不切实际的期望）？

我们非常感谢任何帮助或建议！

Answer 1

Xcode 未能产生真正的错误，这就是他说 CommandsBuilder.

的原因

通常当您遇到此类问题时，请尝试逐块注释您的代码以定位问题。

在这种情况下，如果您评论 if .. { } else { } 并将 if 的两个部分留在那里（只是为了构建它），Xcode 将能够说出实际问题

在这种情况下 LinearGradient 没有 init(colors: ...，所以两行

.mask(Circle().fill(LinearGradient(colors: [Color.black, Color.clear], startPoint: startPoint, endPoint: endPoint)))

应替换为：

.mask(Circle().fill(LinearGradient(gradient: Gradient(colors: [Color.black, Color.clear]), startPoint: startPoint, endPoint: endPoint)))

如果你想使用下面定义的函数，比如 getXoffetInnerShadow，在 .offset 修饰符的参数处，你应该将 return 类型替换为 CGFloat，因为那是只有类型 .offset 接受。

包含控制流语句的闭包不能与结果生成器一起使用 'CommandsBuilder'

Closure containing control flow statement cannot be used with result builder 'CommandsBuilder'

xcode

ios

swift

swiftui

viewbuilder