添加CarPlay UI

Question

我正在使用我當前的iPhone音頻應用程序以在CarPlay中受支持。我已經獲得Apple的批准並獲得了開發權，並觀看了視頻「爲CarPlay啓用您的應用程序」（https://developer.apple.com/videos/play/wwdc2017/719/）。在視頻中有演示如何添加CarPlay UI一塊斯威夫特代碼：

func updateCarWindow() 
{ 
    guard let screen = UIScreen.screens.first(where: 
    { $0.traitCollection.userInterfaceIdiom == .carPlay }) 
    else 
    { 
     // CarPlay is not connected 
     self.carWindow = nil; 
     return 
    } 

    // CarPlay is connected 
    let carWindow = UIWindow(frame: screen.bounds) 
    carWindow.screen = screen 
    carWindow.makeKeyAndVisible() 
    carWindow.rootViewController = CarViewController(nibName: nil, bundle: nil) 
    self.carWindow = carWindow 
} 

我把它重新寫一個Objective-C的版本類似以下內容：

- (void) updateCarWindow 
{ 
    NSArray *screenArray = [UIScreen screens]; 

    for (UIScreen *screen in screenArray) 
    {   
     if (screen.traitCollection.userInterfaceIdiom == UIUserInterfaceIdiomCarPlay) // CarPlay is connected. 
     { 
      // Get the screen's bounds so that you can create a window of the correct size. 
      CGRect screenBounds = screen.bounds; 

      UIWindow *tempCarWindow = [[UIWindow alloc] initWithFrame:screenBounds]; 
      self.carWindow.screen = screen; 
      [self.carWindow makeKeyAndVisible]; 

      // Set the initial UI for the window. 
      UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; 
      UIViewController *rootViewController = [storyboard instantiateViewControllerWithIdentifier:@"VC"]; 

      self.carWindow.rootViewController = rootViewController; 
      self.carWindow = tempCarWindow; 

      // Show the window. 
      self.carWindow.hidden = NO; 

      return; 
     } 
    } 

    // CarPlay is not connected. 
    self.carWindow = nil; 
} 

不過，我發現，無論在真實設備或模擬器上進行測試，UIScreen的屬性「屏幕」總是返回1個元素（主屏幕）。因此，當我的應用程序在模擬器上運行或帶有CarPlay系統的真實汽車上運行時，該應用程序只是空白，並表示「無法連接到」我的應用程序名稱「」（請參閱​​下圖）。儘管我的ViewController有一個簡單的UILabel。

我的問題是：我應該怎麼做才能讓被CarPlay連接我的應用程序？也就是說，我應該如何獲得具有UIUserInterfaceIdiomCarPlay習慣用法的屏幕，而不僅僅是主屏幕？提前致謝。

Answer 1

CarPlay音頻應用程序由MPPlayableContentManager控制。您需要實施MPPlayableContentDelegate和MPPlayableContentDatasource協議才能與CarPlay連接。用戶界面由CarPlay控制 - 您需要做的就是爲tab +表格（數據源）提供數據並響應可播放項目（委託）。