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我想运行Background file transfer
从Background audio agent
但我得到错误的示例代码,在前台应用程序中运行正确。是否可以从后台音频代理运行后台传输?
这里是例子:
string transferFileName = @"http://www.reggaeavenue.com/MP3/leave%20short.mp3";
Uri transferUri = new Uri(Uri.EscapeUriString(transferFileName), UriKind.RelativeOrAbsolute);
BackgroundTransferRequest transferRequest = new BackgroundTransferRequest(transferUri);
transferRequest.Method = "GET";
string downloadFile = "result.mp3";
Uri downloadUri = new Uri("shared/transfers/" + downloadFile, UriKind.RelativeOrAbsolute);
transferRequest.DownloadLocation = downloadUri;
transferRequest.Tag = downloadFile;
transferRequest.TransferPreferences = TransferPreferences.AllowCellularAndBattery;
try
{
BackgroundTransferService.Add(transferRequest);
}
catch (InvalidOperationException ex)
{
MessageBox.Show("Unable to add background transfer request. " + ex.Message);
}
catch (Exception)
{
MessageBox.Show("Unable to add background transfer request.");
}
上的线与加transferRequest到BackgroundTransferService我得到错误:
System.InvalidOperationException: Operation is not valid due to the current state of the object.
at Microsoft.Phone.BackgroundTransfer.BackgroundTransferRequest.SubmitHelper()
at Microsoft.Phone.BackgroundTransfer.BackgroundTransferRequest.Submit()
at Microsoft.Phone.BackgroundTransfer.BackgroundTransferService.Add(BackgroundTransferRequest request)
at Project.AudioPlaybackAgent.AudioPlayer.CreateBackgroundTransfer()
那么,是否可以运行从后台代理transferm?我怎样才能解决这个问题?谢谢
谢谢,我无法找到它。因为我想缓存歌曲然后播放它们。我也想从后台缓存它们。 –
当然,您可以连接背景音频和您的主UI,主UI下载(在后台)文件并更新播放列表。在bacgound代理下载可能很困难,请注意,您有限的时间(30秒)结束调用状态(在发送NotifyComplete()之前) - 如果您的时间用完,您的代理将被终止。 – Romasz
是的,我可以在后台代理下载它,但是当用户尝试使用控件时,什么都不会发生。必须杀死第一个代理,然后创建处理响应的新代码,这对我来说是不可接受的。 –