问题描述
通过.NET Azure Storage Blobs SDK , 获取Blob的MD5值，查看了Azure操作手册中，介绍可以使用 blob.Properties.ContentMD5 属性。
//blob 文件测试 CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient(); CloudBlobContainer container = blobClient.GetContainerReference("file"); CloudBlockBlob blob = container.GetBlockBlobReference(@"image-03.jpg"); blob.UploadFromFile(filePath1, FileMode.OpenOrCreate); Console.WriteLine("md5=" + blob.Properties.ContentMD5);
但是，在项目中，发现SDK更新后(Azure.Storage.Blobs 12.9.1)后，Properties中并没有ContentMD5属性？
问题解答
查看Blob Properties属性的源代码，发现没有了ContentMD5, 但是可以使用ContentHash。如果把ContentHash进行Base64编码后，它的结果就和Azure门户中的Content-MD5值一样：
示例代码如下：
static async Task GetBlobMD5Async(string connectionString,string containerName) { //// Create a BlobServiceClient object which will be used to create a container client BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString); BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName); Console.WriteLine("Listing blobs..."); // List all blobs in the container await foreach (BlobItem blobItem in containerClient.GetBlobsAsync()) { Console.WriteLine("\t" + blobItem.Name); BlobClient bclient = containerClient.GetBlobClient(blobItem.Name); // Get the blob properties BlobProperties properties = await bclient.GetPropertiesAsync(); // Display some of the blob's property values Console.WriteLine($"\t\t ContentLanguage: {properties.ContentLanguage}"); Console.WriteLine($"\t\t ContentType: {properties.ContentType}"); Console.WriteLine($"\t\t CreatedOn: {properties.CreatedOn}"); Console.WriteLine($"\t\t LastModified: {properties.LastModified}"); Console.WriteLine($"\t\t ContentHash: {FormatHashValue(properties.ContentHash)}"); Console.WriteLine($"\t\t ContentMD5: {Convert.ToBase64String(properties.ContentHash)}"); } } public static string FormatHashValue(byte[] contentHash) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < contentHash.Length; i++) { sb.Append(contentHash[i].ToString("x2")); } return sb.ToString(); }
参考资料
如何调用 API 获取 Azure File 存储中文件的 MD5值：https://docs.azure.cn/zh-cn/articles/azure-operations-guide/storage/aog-storage-blob-file-md5
BlobProperties.ContentHash Property: https://learn.microsoft.com/en-us/dotnet/api/azure.storage.blobs.models.blobproperties.contenthash?view=azure-dotnet
Manage blob properties and metadata with .NET ： https://learn.microsoft.com/en-us/azure/storage/blobs/storage-blob-properties-metadata#set-and-retrieve-properties
