[英]Can i pass a Bool as an environment object to subViews in SwiftUI?
[英]How can I access the subviews in SwiftUI?
我正在尝试我们的 SwiftUI 并想在 SwiftUI 组件的行上创建一个组件。 所以,这就是我想要做的:
创建一个扩展View
的新视图
struct CustomComponent: View {
var title: String
var body: some View {
HStack {
Image(systemName: "") // This would be updated through style
Text(verbatim: title)
}
}
}
extension View {
public func componentStyle<S>(_ style: S) -> some View where S : ComponentStyle {
guard self is CustomComponent else {
return AnyView(self)
}
return AnyView(
// Here I want to add the spacing attribute of the style to the HStack.
// Also I want to update the Image with the corresponding style's icon.
// If it's not possible here, please suggest alternate place.
self
.foregroundColor(style.tintColor)
.frame(height: style.height)
)
}
}
public protocol ComponentStyle {
var icon: String { get }
var tintColor: Color { get }
var spacing: CGFloat { get }
var height: CGFloat { get }
}
struct ErrorStyle: ComponentStyle {
var icon: String {
return "xmark.octagon"
}
var tintColor: Color {
return .red
}
var spacing: CGFloat {
return 8
}
var height: CGFloat {
return 24
}
}
我怎样才能实现以下目标:
谢谢
您可以创建自定义EnvironmentKey
:
extension EnvironmentValues {
private struct ComponentStyleKey: EnvironmentKey {
static let defaultValue: ComponentStyle = ErrorStyle()
}
var componentStyle: ComponentStyle {
get { self[ComponentStyleKey] }
set { self[ComponentStyleKey] = newValue }
}
}
并使用它来传递一些ComponentStyle
作为@Environment
变量:
struct ContentView: View {
var body: some View {
CustomComponent(title: "title")
.componentStyle(ErrorStyle())
}
}
struct CustomComponent: View {
@Environment(\.componentStyle) private var style: ComponentStyle
var title: String
var body: some View {
HStack(spacing: style.spacing) {
Image(systemName: style.icon)
Text(verbatim: title)
}
}
}
extension CustomComponent {
func componentStyle<S>(_ style: S) -> some View where S: ComponentStyle {
environment(\.componentStyle, style)
}
}
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