在 flutter 项目中编写 ios 本机 swift 代码时，Xcode 给出错误 Value of type 'FlutterViewController' has no member 'binaryMessenger'

Question

我用命令做了一个flutter项目

flutter create -i swift myProject

然后我使用 cd myProject 将目录更改为 myProject，然后运行 ​​pod setup。它运行得很快，但是当我根据此处的教程将代码添加到 ios/Runner/Runner 目录中的 AppDeligate.swift 时：

https://flutter.dev/docs/development/platform-integration/platform-channels

这是我的 AppDeligate.swift：

  @UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: 
[UIApplicationLaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)

let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
  let batteryChannel = FlutterMethodChannel(name: "samples.flutter.dev/battery",
                                            binaryMessenger: controller.binaryMessenger)
  batteryChannel.setMethodCallHandler({
    (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
    // Note: this method is invoked on the UI thread.
    // Handle battery messages.
      })

return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

我收到错误“‘FlutterViewController’类型的值没有成员‘binaryMessenger’”

我错过了什么吗？

Answer 1

改变这一行

let batteryChannel = FlutterMethodChannel(name: "samples.flutter.dev/battery",
                                        binaryMessenger: controller.binaryMessenger)

至 ->

let batteryChannel = FlutterMethodChannel(name: "samples.flutter.dev/battery",
                                        binaryMessenger: controller as! FlutterBinaryMessenger)

它在最新的 flutter 升级中发生了变化。