如何在webapi上传中获取Multipart文件的流？

Question

我需要使用Stream(Azure Blobstorage)上传文件,而无法找到如何从对象本身获取流.见下面的代码.

我是WebAPI的新手,并使用了一些示例.我正在获取文件和filedata,但我的方法上传它并不正确.因此,我需要将其转换或转换为普通Stream,此刻看起来有点难:)

我知道我需要以ReadAsStreamAsync().Result某种方式使用,但它在foreach循环中崩溃,因为我得到两个provider.Contents(第一个似乎正确,第二个没有).

 [System.Web.Http.HttpPost]
    public async Task<HttpResponseMessage> Upload()
    {
        if (!Request.Content.IsMimeMultipartContent())
        {
            this.Request.CreateResponse(HttpStatusCode.UnsupportedMediaType);
        }

        var provider = GetMultipartProvider();
        var result = await Request.Content.ReadAsMultipartAsync(provider);

        // On upload, files are given a generic name like "BodyPart_26d6abe1-3ae1-416a-9429-b35f15e6e5d5"
        // so this is how you can get the original file name
        var originalFileName = GetDeserializedFileName(result.FileData.First());

        // uploadedFileInfo object will give you some additional stuff like file length,
        // creation time, directory name, a few filesystem methods etc..
        var uploadedFileInfo = new FileInfo(result.FileData.First().LocalFileName);



        // Remove this line as well as GetFormData method if you're not
        // sending any form data with your upload request
        var fileUploadObj = GetFormData<UploadDataModel>(result);

        Stream filestream = null;

        using (Stream stream = new MemoryStream())
        {
            foreach (HttpContent content in provider.Contents)
            {
                BinaryFormatter bFormatter = new BinaryFormatter();
                bFormatter.Serialize(stream, content.ReadAsStreamAsync().Result);
                stream.Position = 0;
                filestream = stream;
            }
        }

        var storage = new StorageServices();
        storage.UploadBlob(filestream, originalFileName);**strong text**



private MultipartFormDataStreamProvider GetMultipartProvider()
    {
        var uploadFolder = "~/App_Data/Tmp/FileUploads"; // you could put this to web.config
        var root = HttpContext.Current.Server.MapPath(uploadFolder);
        Directory.CreateDirectory(root);
        return new MultipartFormDataStreamProvider(root);
    }

Answer 1

这与我几个月前遇到的困境相同（在接管之前捕获上传流MultipartStreamProvider并自动神奇地将流保存到文件中）。建议是继承该类并重写方法......但这对我来说不起作用。MultipartFileStreamProvider:(（我想要将和的功能MultipartFormDataStreamProvider合并到一个 MultipartStreamProvider 中，而不需要自动保存部分）。

这可能会有所帮助；这是由一位 Web API 开发人员编写的，并且来自同一开发人员。