/// <summary>
/// This function is for demo purposes. It adds three files to the background download queue and displays them in the multi-select list.
/// </summary>
private void OnAddButtonClick(object sender, EventArgs e)
{
Dictionary <string, Uri> urlPresets = new Dictionary <string, Uri>
{
{ "21 MB File", new Uri("http://media.ch9.ms/ch9/ecbc/cfcb0ad7-fbdd-47b0-aabf-4da5e3e0ecbc/WP8JumpStart06.mp3", UriKind.Absolute) },
{ "34 MB File", new Uri("http://media.ch9.ms/ch9/7e13/ce6ea97c-e233-4e7c-a74d-ee1c81e37e13/WP8JumpStart04.mp3", UriKind.Absolute) },
{ "92 MB File", new Uri("http://media.ch9.ms/ch9/7e13/ce6ea97c-e233-4e7c-a74d-ee1c81e37e13/WP8JumpStart04.wmv", UriKind.Absolute) },
};
foreach (var preset in urlPresets)
{
Uri saveLocation = new Uri("/shared/transfers/" + preset.Key, UriKind.Relative);
BackgroundTransferRequest request = new BackgroundTransferRequest(preset.Value, saveLocation)
{
TransferPreferences = TransferPreferences.AllowBattery // Note: this will not use cellular data to download
};
TransferMonitor monitor = new TransferMonitor(request, preset.Key);
try
{
BackgroundTransferService.Add(request);
}
catch (Exception err) // An exception is thrown if this transfer is already requested.
{
Debug.WriteLine(err);
continue;
}
monitor.Failed += TransferCanceled;
_list.Add(monitor);
}
}
private void OnCancelButtonClick(object sender, EventArgs e)
{
while (TransfersList.SelectedItems.Count > 0)
{
TransferMonitor monitor = (TransferMonitor)TransfersList.SelectedItems[0];
if (monitor != null)
{
monitor.RequestCancel();
}
_list.Remove(monitor);
}
}
public BackgroundTransferControl()
{
InitializeComponent();
_request = BackgroundTransferService.Requests.FirstOrDefault(s => s.Tag == "Channel9Download");
if (_request != null)
{
_monitor = new TransferMonitor(_request);
_monitor.Failed += TransferFailed;
Control1.DataContext = _monitor;
}
}
private void RestartDownload()
{
try
{
BackgroundTransferService.Remove(_request);
}
catch (Exception)
{
//No need to worry. These errors can be surpressed. We are just making sure the download has been completed cancelled.
}
_request = null;
_monitor = null;
BeginDownload();
}
public async Task DownloadRulesFileAsync()
{
await Task.Yield();
Uri requestUri = new Uri(this.RulesUri);
Uri downloadUri = new Uri(this.localFileName, UriKind.RelativeOrAbsolute);
BackgroundTransferRequest req = new BackgroundTransferRequest(requestUri, downloadUri)
{
TransferPreferences = TransferPreferences.AllowCellularAndBattery
};
BackgroundTransferService.Add(req);
TransferMonitor monitor = new TransferMonitor(req);
monitor.Complete += (sender, args) => BackgroundTransferService.Remove(args.Request);
}
/// <summary>
/// This clears all completed transfers from the transfer queue
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ClearCompletedItems(object sender, EventArgs e)
{
var i = 0;
// Perhaps a goofy looking iteration, but a foreach will not work because items are being removed from _list
while (i < _list.Count)
{
if (_list.ElementAt(i).State == TransferRequestState.Complete)
{
TransferMonitor monitor = _list.ElementAt(i);
monitor.RequestCancel(); //ensures that the request is removed from the queue, even if complete
UnsubscribeMonitor(monitor);
_list.RemoveAt(i);
}
else
{
i++;
}
}
}
private void BeginDownload()
{
using (var storage = IsolatedStorageFile.GetUserStoreForApplication())
{
if (storage.FileExists("/shared/transfers/channel9.mp3"))
{
storage.DeleteFile("/shared/transfers/channel9.mp3");
}
}
_request = new BackgroundTransferRequest(
new Uri("http://media.ch9.ms/ch9/7e13/ce6ea97c-e233-4e7c-a74d-ee1c81e37e13/WP8JumpStart04.mp3",
UriKind.Absolute),
new Uri("/shared/transfers/channel9.mp3", UriKind.Relative))
{
Tag = "Channel9Download", TransferPreferences = TransferPreferences.AllowBattery
};
_monitor = new TransferMonitor(_request);
Control1.DataContext = _monitor;
_monitor.RequestStart(); //This adds request to the BackgroundTransferService queue.
}
public BackgroundTransferQueue()
{
InitializeComponent();
// Load existing background requests into the collection
foreach (BackgroundTransferRequest request in BackgroundTransferService.Requests)
{
var monitor = new TransferMonitor(request);
SubscribeMonitor(monitor);
_list.Add(monitor);
}
TransfersList.DataContext = _list;
// Subscribe buttons to actions
_selectButton.Click += OnSelectButtonClick;
_addButton.Click += OnAddButtonClick;
_cancelButton.Click += OnCancelButtonClick;
_list.CollectionChanged += delegate { _selectButton.IsEnabled = (_list.Count > 0); };
ReloadApplicationBar();
}
private void StartDownload(BackgroundTransferRequest request)
{
if (request.TransferStatus == TransferStatus.Completed)
{
OnCompletion(request);
}
else if (request.TransferStatus == TransferStatus.Unknown)
{
OnFailure(request);
}
else
{
Monitor = new TransferMonitor(request);
Monitor.Complete += (_, args) => { OnCompletion(request); };
Monitor.Failed += (_, args) =>
{
OnFailure(request);
if (args.Request.StatusCode == 206 && args.Request.TotalBytesToReceive > 100000000 && args.Request.TransferPreferences == TransferPreferences.AllowCellularAndBattery)
{
var newRequest = new BackgroundTransferRequest(args.Request.RequestUri, args.Request.DownloadLocation)
{
Tag = args.Request.Tag,
TransferPreferences = TransferPreferences.None,
};
StartDownload(newRequest);
}
};
if (request.TransferStatus == TransferStatus.None)
{
IsolatedStorage.WriteAllText(GetBaseFilename() + CourseTopicNameSuffix, CourseTopicName);
IsolatedStorage.WriteAllText(GetBaseFilename() + LectureTitleSuffix, LectureTitle);
IsolatedStorage.WriteAllText(GetBaseFilename() + IndexSuffix, Index.ToString());
Monitor.RequestStart();
}
}
}
private void UnsubscribeMonitor(TransferMonitor monitor)
{
monitor.Failed -= TransferCanceled;
}
public void SubscribeMonitor(TransferMonitor monitor)
{
UnsubscribeMonitor(monitor); // prevent duplicate subscription
monitor.Failed += TransferCanceled;
}
private TransferMonitorViewModel(TransferMonitor monitor)
{
Monitor = monitor;
}
