c# - 从 Live SDK 调用 BackgroundDownloadAsync 或 BackgroundUploadAsync 后后台任务未知/为空

Question

知道为什么每次调用 BackgrouDownloadAsync 或 BackgroundUploadAsync 时都会在生命周期事件下列出一个“空”任务吗？

我还不能发图片。请参阅http://social.msdn.microsoft.com/Forums/en-US/39944e7d-feb2-4e06-b980-6ff41588ec50/unknown-empty-background-task?forum=wpdevelop中的原始帖子

Answer 1

这是我替换 BackgroundDownloadAsync 和 BackgroundUploadAsync 所做的，省略了任何 try-catch 和错误检查代码。这些调用不会导致“生命周期事件”下拉列表中出现空条目。不确定它是否是由于 VS 2013 中的问题。

下载（这个比较乱，肯定有别的办法）

LiveConnectClient connectClient = new LiveConnectClient(this.Session);
LiveOperationResult _opResult = await connectClient.GetAsync(FileID + "/content");
dynamic _result = _opResult.Result;

CancellationTokenSource cts = new CancellationTokenSource();
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, new Uri(_result.location as string, UriKind.Absolute));
HttpResponseMessage response = await httpClient.SendRequestAsync(request, HttpCompletionOption.ResponseHeadersRead).AsTask(cts.Token);

using (var _stream = (await OutputFile.OpenStreamForWriteAsync()).AsOutputStream())
{
    await response.Content.WriteToStreamAsync(_stream).AsTask(cts.Token);
    await _stream.FlushAsync();
}

上传

LiveConnectClient connectClient = new LiveConnectClient(this.Session);
using (Stream stream = await InputFile.OpenStreamForReadAsync())
{
    using (StreamReader reader = new StreamReader(stream))
    {
        LiveOperationResult _opResult = await connectClient.PutAsync(Awesome2FolderID + "/files/" + OneDriveFilename, reader.ReadToEnd());
    }
}