ios - 如何从swiftui View 调用uikit viewcontroller方法

Question

我已经到处寻找这个问题的答案，但似乎找不到。如何从 swiftUI 调用 viewController 方法(例如单击按钮)？
我有一个看起来像这样的 View Controller :

import Player

class PlayerViewController: UIViewController {
    var player = Player()
    func play() {
        self.player.play()
    }
}

我有一个看起来像这样的包装器:

import SwiftUI
import AVFoundation

struct ProjectEditorPlayerBridge: UIViewControllerRepresentable {

    func makeUIViewController(context: Context) -> PlayerViewController {
        let player = PlayerViewController()
        return player
    }
    
    func updateUIViewController(_ uiViewController: PlayerViewController, context: Context) {
    }
    
    typealias UIViewControllerType = PlayerViewController
}

我希望能够在 swiftUI 中使用按钮操作并调用 viewController play方法一次。我已经看到建议在包装器上设置状态/绑定(bind)并在 updateUIViewController 中调用该方法的答案，但是当我这样做时，我看到它被多次调用，而不仅仅是一次。

Answer 1

这是可能的基于协议(protocol)/配置器的方法，它允许直接使用从代码简单性和可读性来看更合适的操作。

protocol Player { // use protocol to hide implementation
    func play()
}

class PlayerViewController: UIViewController, Player {
    var player = Player()
    func play() {
        self.player.play()
    }
}

struct ProjectEditorPlayerBridge: UIViewControllerRepresentable {
    var configurator: ((Player) -> Void)? // callback

    func makeUIViewController(context: Context) -> PlayerViewController {
        let player = PlayerViewController()

        // callback to provide active component to caller
        configurator?(player)

        return player
    }

    func updateUIViewController(_ uiViewController: PlayerViewController, context: Context) {
    }

    typealias UIViewControllerType = PlayerViewController
}

struct DemoPlayerView: View {
    @State private var player: Player?     // always have current player

    var body: some View {
        VStack {
            ProjectEditorPlayerBridge { self.player = $0 }  // << here !!

            // use player action directly !!
            Button("Play", action: player?.play ?? {})
        }
    }
}