How to detect keyboard events in SwiftUI on macOS?

问题

How can I detect keyboard events in a SwiftUI view on macOS?

I want to be able to use key strokes to control items on a particular screen but it's not clear how I detect keyboard events, which is usually down by overriding the keyDown(_ event: NSEvent) in NSView.

回答1:

There is no built-in native SwiftUI API for this, so far.

Here is just a demo possible approach. Tested with Xcode 11.4 / macOS 10.15.4

struct KeyEventHandling: NSViewRepresentable {
    class KeyView: NSView {
        override var acceptsFirstResponder: Bool { true }
        override func keyDown(with event: NSEvent) {
            super.keyDown(with: event)
            print(">> key \(event.charactersIgnoringModifiers ?? "")")
        }
    }

    func makeNSView(context: Context) -> NSView {
        let view = KeyView()
        DispatchQueue.main.async { // wait till next event cycle
            view.window?.makeFirstResponder(view)
        }
        return view
    }

    func updateNSView(_ nsView: NSView, context: Context) {
    }
}

struct TestKeyboardEventHandling: View {
    var body: some View {
        Text("Hello, World!")
            .background(KeyEventHandling())
    }
}

Output:

来源：https://stackoverflow.com/questions/61153562/how-to-detect-keyboard-events-in-swiftui-on-macos