通过流添加到Azure Blob存储 [英] adding to azure blob storage with stream

问题描述

我正在尝试将通过.net核心Web API接收到的IFormFile添加到azure blob存储中.这些是我设置的属性:

I am trying to add an IFormFile received via a .net core web API to an azure blob storage. These are the properties I have set up:

static internal CloudStorageAccount StorageAccount => 
    new CloudStorageAccount(new StorageCredentials(AccountName, AccessKey, AccessKeyName), true);

// Create a blob client.
static internal CloudBlobClient BlobClient => StorageAccount.CreateCloudBlobClient();

// Get a reference to a container 
static internal CloudBlobContainer Container(string ContainerName) 
                        => BlobClient.GetContainerReference(ContainerName);

static internal CloudBlobContainer ProfilePicContainer 
        => Container(ProfilePicContainerName);

现在我像这样使用ProfilePicContainer:

var Container = BlobStorage.ProfilePicContainer;
string fileName = Guid.NewGuid().ToString("N") + Path.GetExtension(ProfileImage.FileName);
var blockBlob = Container.GetBlockBlobReference(fileName);
var fileStream = ProfileImage.OpenReadStream();
fileStream.Position = 0;
await blockBlob.UploadFromStreamAsync(fileStream);

这给了我以下错误:

Microsoft.WindowsAzure.Storage.StorageException:'无法访问关闭的Stream.'

Microsoft.WindowsAzure.Storage.StorageException: 'Cannot access a closed Stream.'

内部异常 ObjectDisposedException:无法访问关闭的Stream.

Inner Exception ObjectDisposedException: Cannot access a closed Stream.

调试时，我甚至在fileStream.Position = 0之前就已经注意到它的位置已经为0.但是，由于出现了此错误，因此我添加了这一行.同样在等待行，fileStream的_disposed设置为false.

When debugging, I have noticed even before fileStream.Position = 0 it's position is already 0. However I added the line since I was getting this error. Also right at the await line, the fileStream's _disposed is set to false.

此外，关于Blob连接，我尝试为字符串常量AccessKey设置无效的值，并且它显示出完全相同的错误.这意味着我什至不知道它是否是连接.我已经在调试器中检查了blobBlock中的所有值，但是我不知道如何验证它是否已连接.

Moreover regarding the blob connection I have tried setting an invalid value for the string constant AccessKey and it shows the exact same error. Which means I have no idea if it is even connection. I have checked all values within blobBlock in the debugger, but I have no idea how to verify if it is connected.

推荐答案

尝试直接从流中写入时似乎存在一些问题.我能够通过将流转换为字节数组来运行代码.

There seems to be some issue when trying to write directly from the stream. I was able to run the code by converting the stream to a byte array.

await blockBlob.UploadFromByteArrayAsync(ReadFully(fileStream, blockBlob.StreamWriteSizeInBytes),
                            0, (int)fileStream.Length);

ReadFully是对此答案的修改 https://stackoverflow.com/a/221941

static byte[] ReadFully(Stream input, int size)
{
    byte[] buffer = new byte[size];
    using (MemoryStream ms = new MemoryStream())
    {
        int read;
        while ((read = input.Read(buffer, 0, size)) > 0)
        {
            ms.Write(buffer, 0, read);
        }
        return ms.ToArray();
    }
}

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