projectedValue

Discussion 議論

Use the projected value to get a binding to a value that the delegate publishes. Access the projected value by prefixing the name of the delegate instance with a dollar sign ($). For example, you might publish a Boolean value in your extension delegate:

class MyExtensionDelegate: NSObject, WKExtensionDelegate, ObservableObject {
    @Published var isEnabled = false


    // ...
}

If you declare the delegate in your App using the WKExtensionDelegateAdaptor property wrapper, you can get the delegate that SwiftUI instantiates from the environment and access a binding to its published values from any view in your extension:

struct MyView: View {
    @EnvironmentObject private var extensionDelegate: MyExtensionDelegate


    var body: some View {
        Toggle("Enabled", isOn: $extensionDelegate.isEnabled)
    }
}