iOS 開發筆記 - 把玩 Chromecast SDK 播放網路連結（圖片、影片）

買了一隻 Chromecast ，除了試用產品外，也想試試看 Chromecast SDK 。快速翻了一下 iOS App Development - ios sender 文件，還是不得其門而入 XD 最後還是乖乖看範例程式：https://github.com/googlecast/CastVideos-ios

簡言之，我是使用 Cocoapods 管理 Chromecast SDK 的:

$ vim Podfile
pod 'google-cast-sdk'
pod 'google-cast-remote-display-sdk'

接著寫一點程式，參考 CastVideos-ios 內的 CastDeviceController 範例了解整個流程。

總之，若要簡單播放一個 URL ，需要依序完成以下動作：

1. 搜尋 chromecast device 並實作 GCKDeviceScannerListener 偵測裝置
• GCKFilterCriteria *filterCriteria = [GCKFilterCriteria criteriaForAvailableApplicationWithID:kGCKMediaDefaultReceiverApplicationID];
• self.chromecastScanner = [[GCKDeviceScanner alloc] initWithFilterCriteria:filterCriteria];
• [self.chromecastScanner addListener:self];
• [self.chromecastScanner startScan];
2. 透過 - (void)deviceDidComeOnline:(GCKDevice *)device 偵測到後，進行連線
• self.chromecastManager = [[GCKDeviceManager alloc] initWithDevice:self.chooseDevice clientPackageName:[NSBundle mainBundle].bundleIdentifier];
• self.chromecastManager.delegate = self;
• [self.chromecastManager connect];
3. 連線裝置後，透過 Launch application 跟 Chromecast Device 進行溝通
• [self.chromecastManager launchApplication:kGCKMediaDefaultReceiverApplicationID];
4. 透過 - (void)deviceManager:(GCKDeviceManager *)deviceManager didConnectToCastApplication:(GCKApplicationMetadata *)applicationMetadata sessionID:(NSString *)sessionID launchedApplication:(BOOL)launchedApplication; 偵測完成 chromecast app 程式啟動並建立 GCKMediaControlChannel
• self.mediaControlChannel = [[GCKMediaControlChannel alloc] init];
• self.mediaControlChannel.delegate = self;
• [deviceManager addChannel:self.mediaControlChannel];
• [self.mediaControlChannel requestStatus];
5. 播放 Resource，以 http://www.w3schools.com/html/mov_bbb.mp4 為例
• NSMutableArray *tracks = [[NSMutableArray alloc] init];
• GCKMediaMetadata *metadata = [[GCKMediaMetadata alloc] initWithMetadataType:GCKMediaMetadataTypeGeneric];
• GCKMediaInformation *mi = [[GCKMediaInformation alloc] initWithContentID:@"http://www.w3schools.com/html/mov_bbb.mp4" streamType:GCKMediaStreamTypeNone contentType:nil metadata:metadata streamDuration:0 mediaTracks:tracks textTrackStyle:[GCKMediaTextTrackStyle createDefault] customData:nil];
• [self.mediaControlChannel loadMedia:mi autoplay:YES];

如此一來 Chromecast device 就會播放指定的連結啦。