有条件地创建形状 - SwiftUI

Conditional creation of Shapes - SwiftUI

我正在尝试编写一个根据指定条件创建形状的函数,但出现编译错误。

func createShape() -> some Shape {
    switch self.card.shape {
    case .oval:
        return Capsule()
    case .rectangle:
        return Rectangle()
    case .circe:
        return Circle()
    default:
        return Circle()
    }
}

我遇到的错误:

函数声明了一个不透明的 return 类型,但其主体中的 return 语句没有匹配的基础类型

来自 Asperi 的评论和 link:

更改为:

@ViewBuilder
func createShape() -> some View {
    switch self.card.shape {
    case .oval:
        Capsule()
    case .rectangle:
        Rectangle()
    case .circle:
        Circle()
    default:
        Circle()
    }
}

在这个post的帮助下,对我有帮助的是:

创建 AnyShape:

#if canImport(SwiftUI)

import SwiftUI

@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
public struct AnyShape: Shape {
    public var make: (CGRect, inout Path) -> ()

    public init(_ make: @escaping (CGRect, inout Path) -> ()) {
        self.make = make
    }

    public init<S: Shape>(_ shape: S) {
        self.make = { rect, path in
            path = shape.path(in: rect)
        }
    }

    public func path(in rect: CGRect) -> Path {
        return Path { [make] in make(rect, &[=10=]) }
    }
}

#endif

然后:

func createShape() -> AnyShape {
    switch self.card.shape {
    case .oval:
        return AnyShape(Capsule())
    case .rectangle:
        return AnyShape(Rectangle())
    case .circe:
        return AnyShape(Circle())
    }
}