public async void Start()
{
try
{
var downloads = await BackgroundDownloader
.GetCurrentDownloadsAsync()
.AsTask();
foreach (var dl in downloads)
{
dl.Resume();
}
var uploads = await BackgroundUploader
.GetCurrentUploadsAsync()
.AsTask();
foreach (var ul in uploads)
{
ul.StartAsync();
}
}
catch (Exception ex)
{
Log.Write(ex);
}
}
// 加载全部上传任务
private async Task LoadUploadAsync()
{
IReadOnlyList <UploadOperation> uploads = null;
try
{
// 获取所有后台上传任务
uploads = await BackgroundUploader.GetCurrentUploadsAsync();
}
catch (Exception ex)
{
WriteLine(ex.ToString());
return;
}
if (uploads.Count > 0)
{
List <Task> tasks = new List <Task>();
foreach (UploadOperation upload in uploads)
{
// 监视指定的后台上传任务
tasks.Add(HandleUploadAsync(upload, false));
}
await Task.WhenAll(tasks);
}
}
public override IObservable <HttpTransfer> WhenUpdated() => Observable.Create <HttpTransfer>(async(ob, ct) =>
{
var downloads = await BackgroundDownloader
.GetCurrentDownloadsAsync()
.AsTask();
foreach (var download in downloads)
{
download
.AttachAsync()
.AsTask(
ct,
new Progress <DownloadOperation>(_ =>
ob.OnNext(download.FromNative())
)
);
}
var uploads = await BackgroundUploader
.GetCurrentUploadsAsync()
.AsTask();
foreach (var upload in uploads)
{
upload
.AttachAsync()
.AsTask(
ct,
new Progress <UploadOperation>(_ =>
ob.OnNext(upload.FromNative())
)
);
}
});
public HttpTransferTasks()
{
BackgroundUploader
.GetCurrentUploadsAsync()
.AsTask()
.ContinueWith(result =>
{
foreach (var task in result.Result)
{
var config = new TaskConfiguration(task.RequestedUri.ToString(), task.SourceFile.Path)
{
HttpMethod = task.Method,
UseMeteredConnection = task.CostPolicy != BackgroundTransferCostPolicy.UnrestrictedOnly
};
this.Add(new UploadHttpTask(config, task, true));
}
});
BackgroundDownloader
.GetCurrentDownloadsAsync()
.AsTask()
.ContinueWith(result =>
{
foreach (var task in result.Result)
{
var config = new TaskConfiguration(task.RequestedUri.ToString())
{
HttpMethod = task.Method,
UseMeteredConnection = task.CostPolicy != BackgroundTransferCostPolicy.UnrestrictedOnly
};
this.Add(new DownloadHttpTask(config, task, true));
}
});
}
public async Task CancelAll()
{
var uploads = await BackgroundUploader.GetCurrentUploadsAsync();
foreach (var upload in uploads)
{
upload.AttachAsync().Cancel();
}
}
protected override async Task <IEnumerable <HttpTransfer> > GetUploads(QueryFilter filter)
{
var items = await BackgroundUploader
.GetCurrentUploadsAsync()
.AsTask();
return(items
.Select(x => x.FromNative())
.ToList());
}
protected async override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
base.OnNavigatingFrom(e);
var currentUploads = await BackgroundUploader.GetCurrentUploadsAsync();
if (currentUploads.Count > 0)
{
_cts.Cancel();
_cts.Dispose();
}
}
// Enumerate the uploads that were going on in the background while the app was closed.
private async Task DiscoverActiveUploadsAsync()
{
IReadOnlyList <UploadOperation> uploads = null;
try
{
uploads = await BackgroundUploader.GetCurrentUploadsAsync();
}
catch (Exception ex)
{
if (!IsExceptionHandled("Discovery error", ex))
{
throw;
}
return;
}
Log("Loading background uploads: " + uploads.Count);
if (uploads.Count > 0)
{
List <Task> tasks = new List <Task>();
foreach (UploadOperation upload in uploads)
{
Log(String.Format(CultureInfo.CurrentCulture, "Discovered background upload: {0}, Status: {1}",
upload.Guid, upload.Progress.Status));
// Attach progress and completion handlers.
tasks.Add(HandleUploadAsync(upload, false));
}
// Don't await HandleUploadAsync() in the foreach loop since we would attach to the second
// upload only when the first one completed; attach to the third upload when the second one
// completes etc. We want to attach to all uploads immediately.
// If there are actions that need to be taken once uploads complete, await tasks here, outside
// the loop.
await Task.WhenAll(tasks);
}
}
// Enumerate the uploads that were going on in the background while the app was closed.
private async Task DiscoverActiveUploadsAsync()
{
IReadOnlyList <UploadOperation> uploads = null;
try
{
uploads = await BackgroundUploader.GetCurrentUploadsAsync();
}
catch (Exception ex)
{
if (!IsExceptionHandled("Discovery error", ex))
{
var fileUploadResponse = new FileUploadResponse(ex.ToString(), -1, string.Empty, null);
FileUploadError(this, fileUploadResponse);
}
return;
}
if (uploads.Count > 0)
{
List <Task> tasks = new List <Task>();
foreach (UploadOperation upload in uploads)
{
// Attach progress and completion handlers.
tasks.Add(HandleUploadAsync(upload, false));
}
// Don't await HandleUploadAsync() in the foreach loop since we would attach to the second
// upload only when the first one completed; attach to the third upload when the second one
// completes etc. We want to attach to all uploads immediately.
// If there are actions that need to be taken once uploads complete, await tasks here, outside
// the loop.
await Task.WhenAll(tasks);
}
}
