使用 BackgroundUploader 将视频文件上传到服务器

Question

我正在创建面向 Windows 8.0
的 Windows 应用商店应用 我在我的 PC 上安装了 Windows 8.1 预览版，我使用 VS2012 创建了应用程序，并使用 BackgroundUploader 和 createUploadFromStreamAsync 方法使用以下代码实现了文件上传到服务器 -

string url = //url to upload videostring boundray = string.Format("abcboundry");
String header = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\"\r\n" + "Content-Type: {3}\r\n\r\n", boundray, "file", source.Name, "application/octet-stream");
string footer = string.Format("\r\n--{0}--\r\n", boundray);

Stream headerStream = GenerateStreamFromString(header);
Stream footerStream = GenerateStreamFromString(footer);
//Stream dataStream = iRandomstream.AsStream();
Stream dataStream = await source.OpenStreamForReadAsync();

MemoryStream fileDataStream = new MemoryStream();
await headerStream.CopyToAsync(fileDataStream);
await dataStream.CopyToAsync(fileDataStream);
await footerStream.CopyToAsync(fileDataStream);
fileDataStream.Position = 0;

IInputStream stream = fileDataStream.AsInputStream();

BackgroundUploader backgroundUploader = new BackgroundUploader();
backgroundUploader.SetRequestHeader("Content-Type", "multipart/form-data; boundary=" + boundray);
backgroundUploader.Method = "POST";

UploadOperation uploadOpration = await backgroundUploader.CreateUploadFromStreamAsync(new Uri(url), stream);

await HandleUploadAsync(uploadOpration, true);

它对我来说工作正常，但是当在安装了 Windows 8.0 的其他系统上进行测试时，应用程序因 AccessViolationException 未处理而崩溃。尝试读取或写入受保护的内存。这通常表明其他内存已损坏。”在 InitializeComponent. 错误

现在我尝试使用 BackgroundTransferContentPart 进行分段上传，但这段代码没有成功 -

List<BackgroundTransferContentPart> parts = new List<BackgroundTransferContentPart>();
BackgroundTransferContentPart part = new BackgroundTransferContentPart("file", source.Name);
part.SetHeader("Content-Type", "application/octet-stream");
part.SetFile(source);
parts.Add(part);

BackgroundUploader uploader = new BackgroundUploader();
uploader.Method = "POST";
UploadOperation uploadOp = await uploader.CreateUploadAsync(new Uri(url), parts, "form-data",boundray);

await HandleUploadAsync(uploadOp, true);

我可以做些什么来解决我的问题？

如何上传大文件到服务器？

Answer 1

我解决了我的问题。

1. 在 LocalFolder 中创建一个临时原始文件并写入我们需要上传到文件的流（流包含页眉和页脚）
2. 将这个新创建的临时文件同步到存储文件
3. 从存储文件中获取输入流

4. 现在使用此流和用于创建流的相同边界创建上传。

   StorageFile VideoFileStream = await ApplicationData.Current.LocalFolder.CreateFileAsync("tempStream", CreationCollisionOption.OpenIfExists);
   var fs2 = await VideoFileStream.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite);
   IInputStream aaaa= fs2.GetInputStreamAt(0);
   
   BackgroundUploader backgroundUploader = new BackgroundUploader();
   backgroundUploader.SetRequestHeader("Content-Type", "multipart/form-data; boundary=" + boundray);
   backgroundUploader.Method = "POST";
   
   UploadOperation uploadOpration = await backgroundUploader.CreateUploadFromStreamAsync(new Uri(url),aaaa);
   await HandleUploadAsync(uploadOpration, true);
   

Answer 2

您是否尝试过改用 WinRT 流？而不是System.Net.MemoryStream，请尝试Windows.Storage.Streams.InMemoryRandomStream。你可以使用RandomAccessStream.CopyAsync()来填写。