SwiftUI macOS响应子视图中的菜单栏操作

Question

我的macOS应用程序中有一个视图，当用户按下菜单栏中的undo和redo按钮时，需要通知该视图。在AppDelegate中，我让IBActions在用户按下undo/redo按钮时触发。IBAction通过通知中心发布通知，如下图所示：

extension Notification.Name {

    static let undo = Notification.Name("undo")
    static let redo = Notification.Name("redo")
}

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {

    @IBAction func menuBarUndo(_ sender: Any) {
        print("AppDelegate: pressed undo")
        nc.post(name: .undo, object: nil)
    }


    @IBAction func menuBarRedo(_ sender: Any) {
        print("AppDelegate: pressed redo")
        nc.post(name: .redo, object: nil)


    }

    let nc = NotificationCenter.default

    // applicationDidFinishLaunching and applicationWillTerminate not shown for brevity

}

在我的ContentView中，有一个函数需要在用户按下undo/redo按钮时触发。它需要从ContentView内部触发，因为它依赖于该视图中包含的数据。如何在ContentView中订阅通知才能触发函数？

Answer 1

在ContentView中，In可以如下所示

var body: some View {
    VStack {
        Text("Demo for receiving notifications")
        .onReceive(NotificationCenter.default.publisher(for: .undo)) { _ in
            /// call undo action
        }
        .onReceive(NotificationCenter.default.publisher(for: .redo)) { _ in
            /// call redo action
        }
    }
}