离线下载实现逻辑

• 第一步是先按照开发环境配置搭建好工程环境

• 第二步

  • 把 courseDownload 整个文件夹拖入工程
  • 把 TFPublic（工具类）整个文件夹拖入工程
  • 把 Assets.xcassets的FDemoAssetss文件夹拖入工程

 let downloadManager = TalkfunDownloadManager.share()

创建下载的对象

创建下载任务并启动下载

• 支持将课程数据下载到本地，在无网络环境正常播放。
• 进入回放时，需要传入回放的access_token和playbackID，SDK会根据传入的access_token和playbackID从本地检索是否有该课程的缓存文件，如果有缓存则读取本地缓存播放，否则去请求网络。

                let access_token  = "fsdfsdfsdfasdfasfs"
                 let playback_ID  = "123"

                //创建下载任务
                self.downloadManager.appendDownload(withAccessKey: token, playbackID: playback_ID, title: "")
                //启动下载
                self.downloadManager.startDownload(playback_ID)

下载进度

• TalkfunDownloadManagerDelegate

- (void)downloadProgress:(TalkfunDownloadProgressModel*_Nullable)progressModel

• TalkfunDownloadProgressModel 参数

@interface TalkfunDownloadProgressModel : NSObject
@property(nonatomic,strong)NSString* _Nullable playbackID;//课程id
@property(nonatomic,assign)CGFloat         totalSize;//课程总大小
@property(nonatomic,assign)CGFloat         downloadedSize;//已下载的大小
@end

下载状态

• TalkfunDownloadManagerDelegate

- (void)downloadStatus:(TalkfunDownloadStatusModel*_Nullable)statusModel

• TalkfunDownloadStatusModel 参数

@interface TalkfunDownloadStatusModel : NSObject
@property(nonatomic,strong)NSString* _Nullable   playbackID;//课程id
@property(nonatomic,assign)CGFloat   downloadedSize;//已下载的大小
@property(nonatomic,assign)CGFloat   duration;      //课程长度
@property(nonatomic,assign)CGFloat   totalSize;      ///课程总大小
@property(nonatomic,assign)TalkfunDownloadStatus downloadStatus;
@property (nonatomic, copy) NSString * _Nullable thumb;
@end

下载发生错误

• TalkfunDownloadManagerDelegate

- (void)downloadError:(TalkfuError *_Nullable)error

• TalkfuError 参数

@interface TalkfuError : NSObject
@property(nonatomic,strong)NSString *_Nullable playbackID;//课程id
@property(nonatomic,strong)NSString *_Nullable reasonDescription;//原因描述
@property(nonatomic,assign)NSString *_Nullable statusCode;//状态码
@property(nonatomic,assign)NSString *_Nullable  URL;
@end

下载完成后可通过课程access_token离线观看

```