在Azure存储上，CanGenerateSasUri始终为false

c#

我有一个使用 Azure 存储的 ASP .Net Core 3.1 Web API。为此，它使用了 Microsoft.Azure.Storage.Blob 库。NuGet 包管理器通知我该包已被弃用，我应该使用 Azure.Storage.Blobs。我这样做了，并继续修复由于此更改而导致的所有损坏代码。在我找到为客户端生成共享访问签名 (SAS) 的代码之前，我没有遇到很多问题。无论如何，我设法通过以下代码使其工作：

https://docs.microsoft.com/en-us/azure/storage/blobs/sas-service-create?tabs=dotnet

private static Uri GetServiceSasUriForContainer(BlobContainerClient containerClient,
                                          string storedPolicyName = null)
{
    // Check whether this BlobContainerClient object has been authorized with Shared Key.
    if (containerClient.CanGenerateSasUri)
    {
        // Create a SAS token that's valid for one hour.
        BlobSasBuilder sasBuilder = new BlobSasBuilder()
        {
            BlobContainerName = containerClient.Name,
            Resource = "c"
        };

        if (storedPolicyName == null)
        {
            sasBuilder.ExpiresOn = DateTimeOffset.UtcNow.AddHours(1);
            sasBuilder.SetPermissions(BlobContainerSasPermissions.Read);
        }
        else
        {
            sasBuilder.Identifier = storedPolicyName;
        }

        Uri sasUri = containerClient.GenerateSasUri(sasBuilder);
        Console.WriteLine("SAS URI for blob container is: {0}", sasUri);
        Console.WriteLine();

        return sasUri;
    }
    else
    {
        Console.WriteLine(@"BlobContainerClient must be authorized with Shared Key 
                          credentials to create a service SAS.");
        return null;
    }
}

但是，该行Uri sasUri = containerClient.GenerateSasUri(sasBuilder);给了我一个错误，经过进一步研究，我改为使用：

StorageSharedKeyCredential credential = new StorageSharedKeyCredential(storageAccountName, storageAccountKey);

但是，我也不得不注释掉该行，if (containerClient.CanGenerateSasUri)因为它总是错误的。显然这是因为“必须使用共享密钥凭据授权 BlobContainerClient 才能创建服务 SAS。” 但据我所知，我使用的是共享密钥凭据。我没有使用 Azure AD 身份验证（即使我知道这是推荐的方法）。我的 BlobServiceClient 正在像这样初始化：

string storageConnectionString = $"DefaultEndpointsProtocol=https;AccountName=propworx;AccountKey={storageAccountKey};EndpointSuffix=core.windows.net";
BlobServiceClient blobServiceClient = new BlobServiceClient(storageConnectionString);

有谁知道为什么 CanGenerateSasUri 是假的？

回答

        var storageAccountName = "xxx";
        var storageAccountKey = "xxx";
        var container_name = "xxx";

        StorageSharedKeyCredential credential = new StorageSharedKeyCredential(storageAccountName, storageAccountKey);

        //build the blob container url
        string blobcontainer_url = string.Format("https://{0}.blob.core.windows.net/{1}", storageAccountName, container_name);

        //directly build BlobContainerClient, then pass it to GetServiceSasUriForContainer() method
        BlobContainerClient blobContainer = new BlobContainerClient(new Uri(blobcontainer_url), credential);

        Uri mysasuri = GetServiceSasUriForContainer(blobContainer, null);