When was a block blob created in azure?

问题

The blob reference contains a Properties property that has a LastModified of DateTimeOffset?. However, I can't find when was the creation date(time) of the blob. Is there a standard API I can use or I need to store that in the meta?

    public async Task<IBlobMeta> GetBlobMetaAsync(string blobId)
        {
            if (IsNullOrWhiteSpace(blobId))
                throw new ArgumentException("Value cannot be null or whitespace.", nameof(blobId));

            var blob = await EnsureGetBlobById(blobId);
            await blob.FetchAttributesAsync();

            string clientBlobName;
            blob.Metadata.TryGetValue(BlobNameMetaKey, out clientBlobName);

            var length = blob.Properties.Length;
            var md5 = blob.Properties.ContentMD5;
            var lastModified = blob.Properties.LastModified.Value.ToUniversalTime().DateTime;
            var dateCreated= blob.Properties.???????;
            return new AzureBlobMeta(blobId, clientBlobName, length, md5, dateCreated);
  }

回答1:

The Created date property has been added in Storage Client Library, starting with version 9.2.0:

Blobs: Added support for blob creation time property.

(Available on Nuget since May 23 '18)

Here's how it's declared in BlobProperties.cs:

/// <summary>
/// Gets the the creation time for the blob, expressed as a UTC value.
/// </summary>
/// <value>A <see cref="DateTimeOffset"/> containing the blob's creation time, in UTC format.</value>
public DateTimeOffset? Created { get; internal set; }

The type is nullable DateTimeOffset, same as LastModified property.

---

The source of the value comes from x-ms-creation-time header in the REST API, which was added in version 2017-11-09:

x-ms-creation-time Version 2017-11-09 and newer. The date/time at which the blob was created. The date format follows RFC 1123.

回答2:

Is there a standard API I can use or I need to store that in the meta?

As of today, you would need to store this information in form of blob metadata. There's no API which would tell you when a blob was created. Last Modified property of the blob tells you when a blob was last modified. This could be because a blob's content was changed or either it's properties or metadata was changed.

来源：https://stackoverflow.com/questions/41287749/when-was-a-block-blob-created-in-azure