public override void ViewDidLoad()
{
base.ViewDidLoad();
// Add a bar button item to exit the app manually. Don't do this in productive apps - Apple won't approve it!
// We have it here to demonstrate that iOS will relaunch the app if a download has finished.
this.NavigationItem.LeftBarButtonItem = new UIBarButtonItem("Quit", UIBarButtonItemStyle.Plain, delegate {
// Store all download info to disk. If iOS terminates the app, this would be handled in WillTerminate().
// However this won't be triggered if the app is killed manually by this call.
AppDelegate.SerializeAvailableDownloads();
// Exit application with code 3.
MusicListController.Exit(3);
});
// Magic line: allows starting music playback when app is backgrounded or even terminated!
UIApplication.SharedApplication.BeginReceivingRemoteControlEvents();
// We must set up an AVAudioSession and tell iOS we want to playback audio. Only then can music playback be used in the background.
var audioSession = AVAudioSession.SharedInstance();
audioSession.SetCategory(AVAudioSessionCategory.Playback);
audioSession.SetActive(true);
// Add a bar button item to reset all downloads.
var refreshBtn = new UIBarButtonItem(UIBarButtonSystemItem.Refresh);
refreshBtn.Clicked += async(sender, e) => {
// Stop audio.
this.PlayAudio(null);
var pendingTasks = await this.Session.GetTasks2Async();
if (pendingTasks != null && pendingTasks.DownloadTasks != null)
{
foreach (var task in pendingTasks.DownloadTasks)
{
task.Cancel();
}
}
AppDelegate.AvailableDownloads.ForEach(info => info.Reset(true));
AppDelegate.ResetAvailableDownloads();
((DelegateTableViewSource <DownloadInfo>)(this.TableView.Source)).Items = AppDelegate.AvailableDownloads;
this.TableView.ReloadData();
AppDelegate.SerializeAvailableDownloads();
};
// Add a button to stops playback.
this.stopBtn = new UIBarButtonItem(UIBarButtonSystemItem.Stop)
{
Enabled = false
};
this.stopBtn.Clicked += (sender, e) => this.StopAudio();
this.NavigationItem.RightBarButtonItems = new UIBarButtonItem[] { refreshBtn, this.stopBtn };
// Initialize our session config. We use a background session to enabled out of process uploads/downloads. Note that there are other configurations available:
// - DefaultSessionConfiguration: behaves like NSUrlConnection. Used if *background* transfer is not required.
// - EphemeralSessionConfiguration: use if you want to achieve something like private browsing where all sesion info (e.g. cookies) is kept in memory only.
using (var sessionConfig = UIDevice.CurrentDevice.CheckSystemVersion(8, 0)
? NSUrlSessionConfiguration.CreateBackgroundSessionConfiguration(SessionId)
: NSUrlSessionConfiguration.BackgroundSessionConfiguration(SessionId))
{
// Allow downloads over cellular network too.
sessionConfig.AllowsCellularAccess = true;
// We want our app to be launched if required.
//sessionConfig.SessionSendsLaunchEvents = true;
// Give the OS a hint about what we are downloading. This helps iOS to prioritize. For example "Background" is used to download data that was not requested by the user and
// should be ready if the app gets activated.
sessionConfig.NetworkServiceType = NSUrlRequestNetworkServiceType.Default;
// Configure how many downloads we allow at the same time. Set to 2 to see that further downloads start once the first two have been completed.
sessionConfig.HttpMaximumConnectionsPerHost = 2;
// Create a session delegate and the session itself
// Initialize the session itself with the configuration and a session delegate.
var sessionDelegate = new SessionDelegate(this);
this.Session = NSUrlSession.FromConfiguration(sessionConfig, (INSUrlSessionDelegate)sessionDelegate, null);
}
this.TableView.Source = new DelegateTableViewSource <DownloadInfo>(this.TableView, "MUSIC_CELL")
{
Items = AppDelegate.AvailableDownloads,
GetCellFunc = (item, cell) =>
{
var musicCell = (MusicCell)cell;
musicCell.InitFromDownloadInfo(item);
return(musicCell);
},
RowSelectedFunc = (downloadInfo, cell, indexPath) =>
{
// If a row gets tapped, download or play.
if (downloadInfo.Status != DownloadInfo.STATUS.Completed & downloadInfo.Status != DownloadInfo.STATUS.Downloading)
{
// Queue download.
this.EnqueueDownloadAsync(downloadInfo);
// Update UI once more. Download initialization might have failed .
((MusicCell)cell).InitFromDownloadInfo(downloadInfo);
this.TableView.ReloadRows(new NSIndexPath[] { indexPath }, UITableViewRowAnimation.None);
}
else if (downloadInfo.Status == DownloadInfo.STATUS.Completed)
{
// Play MP3.
this.currentSongIndex = indexPath.Row;
this.PlayAudio(downloadInfo);
}
}
};
this.TableView.EstimatedRowHeight = 100;
this.TableView.RowHeight = UITableView.AutomaticDimension;
}
public SessionDelegate(MusicListController controller) : base()
{
this.controller = controller;
}