目前针对Carplay的教程，包括官方文档，主要是通过SceneDelegate来实现，按照文档我们会定义SceneDelegate和Info.plist
并通过SceneDelegate来提供Carplay所需的 CPTemplateApplicationScene, 但如果你的应用是SwiftUI原生应用，使用SwiftUI Lifecycle (SwiftUI.App), 运行后往往会产生如下报错:
Thread 1: "Application does not implement CarPlay template application lifecycle methods in its scene delegate."
即便我们已在SceneDelegate中正确实现了相关方法，但报错仍会出现，像是SceneDelegate并没有生效。
一些解决方案，涉及到不再将 SwiftUI.App 作为 @main 的入口，而是将 AppDelegate 作为入口
这虽然可以让Carplay正确运行，但会导致我们必须使用传统的方式来管理App的生命周期，而不是使用SwiftUI的生命周期，对原生SwiftUI的开发者来说，这是一个不太友好的解决方案。
这种实现方案的代码可以参考 https://github.com/vanities/carplay-swiftui
正确做法
经过艰难的搜索，我在 https://stackoverflow.com/a/76398654/1170477 这个帖子上找到了解决方案。
我们需要在项目的编译设置中关闭 Application Scene Manifest (Generation) 这个选项，这样我们编辑的Info.plist才不会被自动生成的所覆盖。
完整的接入步骤
在Info.plist中定义UIApplicationSceneManifest
将以下配置插入到Info.plist顶级
<key>UIApplicationSceneManifest</key>
<dict>
<key>UIApplicationSupportsMultipleScenes</key>
<false/>
<key>UISceneConfigurations</key>
<dict>
<key>CPTemplateApplicationSceneSessionRoleApplication</key>
<array>
<dict>
<key>UISceneClassName</key>
<string>CPTemplateApplicationScene</string>
<key>UISceneConfigurationName</key>
<string>CarPlay</string>
<key>UISceneDelegateClassName</key>
<string>$(PRODUCT_MODULE_NAME).CarPlaySceneDelegate</string>
</dict>
</array>
<key>UIWindowSceneSessionRoleApplication</key>
<array>
<dict>
<key>UISceneClassName</key>
<string>UIWindowScene</string>
<key>UISceneConfigurationName</key>
<string>Phone</string>
<key>UISceneDelegateClassName</key>
<string>$(PRODUCT_MODULE_NAME).SceneDelegate</string>
</dict>
</array>
</dict>
</dict>
如果不使用SceneDelegate，只单独为Carplay设置一个专用SceneDelegate也是可以的，Info.plist如下
<key>UIApplicationSceneManifest</key>
<dict>
<key>UIApplicationSupportsMultipleScenes</key>
<false/>
<key>UISceneConfigurations</key>
<dict>
<key>CPTemplateApplicationSceneSessionRoleApplication</key>
<array>
<dict>
<key>UISceneClassName</key>
<string>CPTemplateApplicationScene</string>
<key>UISceneConfigurationName</key>
<string>CarPlay</string>
<key>UISceneDelegateClassName</key>
<string>$(PRODUCT_MODULE_NAME).CarPlaySceneDelegate</string>
</dict>
</array>
</dict>
</dict>
定义CarplaySceneDelegate
示例代码如下
class CarPlaySceneDelegate: UIResponder, CPTemplateApplicationSceneDelegate {
private var interfaceController: CPInterfaceController?
/// 1. CarPlay connected
func templateApplicationScene(
_ templateApplicationScene: CPTemplateApplicationScene,
didConnect interfaceController: CPInterfaceController
) {
// 2
self.interfaceController = interfaceController
// 3
setInformationTemplate()
}
/// 4. Information template
private func setInformationTemplate() {
// 5 - Setting the content for the template
let sections: [CPListSection] = [
.init(items: [
.init(text: "Hello, CarPlay!", detailText: "This is a test app.")
])
]
// 6 - Selecting the template
let infoTemplate = CPListTemplate(title: "Hello World", sections: sections)
// 7 - Setting the information template as the root template
interfaceController?.setRootTemplate(infoTemplate,
animated: true,
completion: { success, error in
if let error = error {
debugPrint("Error: \(error)")
}
})
}
}
定义了这两个部分，Carplay的模板应该就已可以正常运行了，如果不能运行，可能是Capability等前置配置没有完成，请参考官方文档。
附: SceneDelegate 的示例代码
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
// Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
// If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
// This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
// Create the SwiftUI view that provides the window contents.
// let contentView = Text("Hello World")
//
// // Use a UIHostingController as window root view controller.
// if let windowScene = scene as? UIWindowScene {
// let window = UIWindow(windowScene: windowScene)
// window.rootViewController = UIHostingController(rootView: contentView)
// self.window = window
// window.makeKeyAndVisible()
// }
}
func sceneDidDisconnect(_ scene: UIScene) {
// Called as the scene is being released by the system.
// This occurs shortly after the scene enters the background, or when its session is discarded.
// Release any resources associated with this scene that can be re-created the next time the scene connects.
// The scene may re-connect later, as its session was not necessarily discarded (see `application:didDiscardSceneSessions` instead).
}
func sceneDidBecomeActive(_ scene: UIScene) {
// Called when the scene has moved from an inactive state to an active state.
// Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
}
func sceneWillResignActive(_ scene: UIScene) {
// Called when the scene will move from an active state to an inactive state.
// This may occur due to temporary interruptions (ex. an incoming phone call).
}
func sceneWillEnterForeground(_ scene: UIScene) {
// Called as the scene transitions from the background to the foreground.
// Use this method to undo the changes made on entering the background.
}
func sceneDidEnterBackground(_ scene: UIScene) {
// Called as the scene transitions from the foreground to the background.
// Use this method to save data, release shared resources, and store enough scene-specific state information
// to restore the scene back to its current state.
}
}