使用 .NET 11.x 版用戶端連結庫 Azure Blob 儲存體程式代碼範例

文章
04/03/2023

本文說明使用適用於 .NET 之 Azure Blob 儲存體客戶端連結庫 11.x 版的程式代碼範例。

在 2023 年 3 月 31 日，我們已淘汰對不符合目前 Azure SDK 指導方針的 Azure SDK 連結庫支援。新的 Azure SDK 連結庫會定期更新，以推動一致的體驗，並強化您的安全性狀態。建議您轉換至新的 Azure SDK 連結庫，以利用新功能和重大安全性更新。

雖然舊版連結庫仍可在 2023 年 3 月 31 日之後使用，但不再收到 Microsoft 的官方支援和更新。如需詳細資訊，請參閱支援淘汰公告。

建立快照集

若要使用適用於 .NET 的 Azure 儲存體用戶端程式庫 11.x 版來建立區塊 Blob 的快照集，請使用下列其中一種方法：

下列程式碼範例說明如何使用 11.x 版建立快照集。此範例會在建立快照集時為其指定其他中繼資料。

private static async Task CreateBlockBlobSnapshot(CloudBlobContainer container)
{
    // Create a new block blob in the container.
    CloudBlockBlob baseBlob = container.GetBlockBlobReference("sample-base-blob.txt");

    // Add blob metadata.
    baseBlob.Metadata.Add("ApproxBlobCreatedDate", DateTime.UtcNow.ToString());

    try
    {
        // Upload the blob to create it, with its metadata.
        await baseBlob.UploadTextAsync(string.Format("Base blob: {0}", baseBlob.Uri.ToString()));

        // Sleep 5 seconds.
        System.Threading.Thread.Sleep(5000);

        // Create a snapshot of the base blob.
        // You can specify metadata at the time that the snapshot is created.
        // If no metadata is specified, then the blob's metadata is copied to the snapshot.
        Dictionary<string, string> metadata = new Dictionary<string, string>();
        metadata.Add("ApproxSnapshotCreatedDate", DateTime.UtcNow.ToString());
        await baseBlob.CreateSnapshotAsync(metadata, null, null, null);
        Console.WriteLine(snapshot.SnapshotQualifiedStorageUri.PrimaryUri);
    }
    catch (StorageException e)
    {
        Console.WriteLine(e.Message);
        Console.ReadLine();
        throw;
    }
}

刪除快照集

若要使用適用於 .NET 的 Azure 儲存體用戶端程式庫 11.x 版來刪除 Blob 及其快照集，請使用下列其中一種 Blob 刪除方法，並納入 DeleteSnapshotsOption 列舉：

下列程式碼範例說明如何在 .NET 中刪除 Blob 及其快照集，其中，blockBlob 是 [CloudBlockBlob][dotnet_CloudBlockBlob] 類型的物件：

await blockBlob.DeleteIfExistsAsync(DeleteSnapshotsOption.IncludeSnapshots, null, null, null);

建立預存的存取原則

若要在具有適用於 Azure 記憶體之 .NET 用戶端連結庫 11.x 版的容器上建立預存存取原則，請呼叫下列其中一種方法：

下列範例建立的預存存取原則只有一天的效期，且會授與讀取、寫入和列出權限：

private static async Task CreateStoredAccessPolicyAsync(CloudBlobContainer container, string policyName)
{
    // Create a new stored access policy and define its constraints.
    // The access policy provides create, write, read, list, and delete permissions.
    SharedAccessBlobPolicy sharedPolicy = new SharedAccessBlobPolicy()
    {
        // When the start time for the SAS is omitted, the start time is assumed to be the time when Azure Storage receives the request.
        SharedAccessExpiryTime = DateTime.UtcNow.AddHours(24),
        Permissions = SharedAccessBlobPermissions.Read | SharedAccessBlobPermissions.List |
            SharedAccessBlobPermissions.Write
    };

    // Get the container's existing permissions.
    BlobContainerPermissions permissions = await container.GetPermissionsAsync();

    // Add the new policy to the container's permissions, and set the container's permissions.
    permissions.SharedAccessPolicies.Add(policyName, sharedPolicy);
    await container.SetPermissionsAsync(permissions);
}

建立容器或 blob 的服務 SAS

若要建立容器的服務 SAS，請呼叫 CloudBlobContainer.GetSharedAccessSignature 方法。

private static string GetContainerSasUri(CloudBlobContainer container,
                                         string storedPolicyName = null)
{
    string sasContainerToken;

    // If no stored policy is specified, create a new access policy and define its constraints.
    if (storedPolicyName == null)
    {
        // Note that the SharedAccessBlobPolicy class is used both to define
        // the parameters of an ad hoc SAS, and to construct a shared access policy
        // that is saved to the container's shared access policies.
        SharedAccessBlobPolicy adHocPolicy = new SharedAccessBlobPolicy()
        {
            // When the start time for the SAS is omitted, the start time is assumed
            // to be the time when the storage service receives the request. Omitting
            // the start time for a SAS that is effective immediately helps to avoid clock skew.
            SharedAccessExpiryTime = DateTime.UtcNow.AddHours(24),
            Permissions = SharedAccessBlobPermissions.Write | SharedAccessBlobPermissions.List
        };

        // Generate the shared access signature on the container,
        // setting the constraints directly on the signature.
        sasContainerToken = container.GetSharedAccessSignature(adHocPolicy, null);

        Console.WriteLine("SAS for blob container (ad hoc): {0}", sasContainerToken);
        Console.WriteLine();
    }
    else
    {
        // Generate the shared access signature on the container. In this case,
        // all of the constraints for the shared access signature are specified
        // on the stored access policy, which is provided by name. It is also possible
        // to specify some constraints on an ad hoc SAS and others on the stored access policy.
        sasContainerToken = container.GetSharedAccessSignature(null, storedPolicyName);

        Console.WriteLine("SAS for container (stored access policy): {0}", sasContainerToken);
        Console.WriteLine();
    }

    // Return the URI string for the container, including the SAS token.
    return container.Uri + sasContainerToken;
}

建立 blob 的服務 SAS

若要建立 blob 的服務 SAS，請呼叫 CloudBlob.GetSharedAccessSignature 方法。

private static string GetBlobSasUri(CloudBlobContainer container,
                                    string blobName,
                                    string policyName = null)
{
    string sasBlobToken;

    // Get a reference to a blob within the container.
    // Note that the blob may not exist yet, but a SAS can still be created for it.
    CloudBlockBlob blob = container.GetBlockBlobReference(blobName);

    if (policyName == null)
    {
        // Create a new access policy and define its constraints.
        // Note that the SharedAccessBlobPolicy class is used both to define the parameters
        // of an ad hoc SAS, and to construct a shared access policy that is saved to
        // the container's shared access policies.
        SharedAccessBlobPolicy adHocSAS = new SharedAccessBlobPolicy()
        {
            // When the start time for the SAS is omitted, the start time is assumed to be
            // the time when the storage service receives the request. Omitting the start time
            // for a SAS that is effective immediately helps to avoid clock skew.
            SharedAccessExpiryTime = DateTime.UtcNow.AddHours(24),
            Permissions = SharedAccessBlobPermissions.Read |
                          SharedAccessBlobPermissions.Write |
                          SharedAccessBlobPermissions.Create
        };

        // Generate the shared access signature on the blob,
        // setting the constraints directly on the signature.
        sasBlobToken = blob.GetSharedAccessSignature(adHocSAS);

        Console.WriteLine("SAS for blob (ad hoc): {0}", sasBlobToken);
        Console.WriteLine();
    }
    else
    {
        // Generate the shared access signature on the blob. In this case, all of the constraints
        // for the SAS are specified on the container's stored access policy.
        sasBlobToken = blob.GetSharedAccessSignature(null, policyName);

        Console.WriteLine("SAS for blob (stored access policy): {0}", sasBlobToken);
        Console.WriteLine();
    }

    // Return the URI string for the container, including the SAS token.
    return blob.Uri + sasBlobToken;
}

建立帳戶 SAS

若要建立容器的帳戶 SAS，請呼叫 CloudStorageAccount.GetSharedAccessSignature 方法。

下列程式碼範例會建立適用於 Blob 和檔案服務的帳戶 SAS，並提供用戶端權限讀取、寫入和列出權限來存取服務層級 API。帳戶 SAS 會將通訊協定限制為 HTTPS，因此必須使用 HTTPS 提出要求。請記得以您自己的值取代角括號中的預留位置值：

static string GetAccountSASToken()
{
    // To create the account SAS, you need to use Shared Key credentials. Modify for your account.
    const string ConnectionString = "DefaultEndpointsProtocol=https;AccountName=<storage-account>;AccountKey=<account-key>";
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConnectionString);

    // Create a new access policy for the account.
    SharedAccessAccountPolicy policy = new SharedAccessAccountPolicy()
        {
            Permissions = SharedAccessAccountPermissions.Read | 
                          SharedAccessAccountPermissions.Write | 
                          SharedAccessAccountPermissions.List,
            Services = SharedAccessAccountServices.Blob | SharedAccessAccountServices.File,
            ResourceTypes = SharedAccessAccountResourceTypes.Service,
            SharedAccessExpiryTime = DateTime.UtcNow.AddHours(24),
            Protocols = SharedAccessProtocol.HttpsOnly
        };

    // Return the SAS token.
    return storageAccount.GetSharedAccessSignature(policy);
}

從用戶端使用帳戶 SAS

在此程式碼片段中，將 <storage-account> 預留位置取代為您的儲存體帳戶名稱。

static void UseAccountSAS(string sasToken)
{
    // Create new storage credentials using the SAS token.
    StorageCredentials accountSAS = new StorageCredentials(sasToken);
    // Use these credentials and the account name to create a Blob service client.
    CloudStorageAccount accountWithSAS = new CloudStorageAccount(accountSAS, "<storage-account>", endpointSuffix: null, useHttps: true);
    CloudBlobClient blobClientWithSAS = accountWithSAS.CreateCloudBlobClient();

    // Now set the service properties for the Blob client created with the SAS.
    blobClientWithSAS.SetServiceProperties(new ServiceProperties()
    {
        HourMetrics = new MetricsProperties()
        {
            MetricsLevel = MetricsLevel.ServiceAndApi,
            RetentionDays = 7,
            Version = "1.0"
        },
        MinuteMetrics = new MetricsProperties()
        {
            MetricsLevel = MetricsLevel.ServiceAndApi,
            RetentionDays = 7,
            Version = "1.0"
        },
        Logging = new LoggingProperties()
        {
            LoggingOperations = LoggingOperations.All,
            RetentionDays = 14,
            Version = "1.0"
        }
    });

    // The permissions granted by the account SAS also permit you to retrieve service properties.
    ServiceProperties serviceProperties = blobClientWithSAS.GetServiceProperties();
    Console.WriteLine(serviceProperties.HourMetrics.MetricsLevel);
    Console.WriteLine(serviceProperties.HourMetrics.RetentionDays);
    Console.WriteLine(serviceProperties.HourMetrics.Version);
}

Blob 的開放式並行存取

程式碼範例：

public void DemonstrateOptimisticConcurrencyBlob(string containerName, string blobName)
{
    Console.WriteLine("Demonstrate optimistic concurrency");

    // Parse connection string and create container.
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConnectionString);
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
    CloudBlobContainer container = blobClient.GetContainerReference(containerName);
    container.CreateIfNotExists();

    // Create test blob. The default strategy is last writer wins, so
    // write operation will overwrite existing blob if present.
    CloudBlockBlob blockBlob = container.GetBlockBlobReference(blobName);
    blockBlob.UploadText("Hello World!");

    // Retrieve the ETag from the newly created blob.
    string originalETag = blockBlob.Properties.ETag;
    Console.WriteLine("Blob added. Original ETag = {0}", originalETag);

    /// This code simulates an update by another client.
    string helloText = "Blob updated by another client.";
    // No ETag was provided, so original blob is overwritten and ETag updated.
    blockBlob.UploadText(helloText);
    Console.WriteLine("Blob updated. Updated ETag = {0}", blockBlob.Properties.ETag);

    // Now try to update the blob using the original ETag value.
    try
    {
        Console.WriteLine(@"Attempt to update blob using original ETag
                            to generate if-match access condition");
        blockBlob.UploadText(helloText, accessCondition: AccessCondition.GenerateIfMatchCondition(originalETag));
    }
    catch (StorageException ex)
    {
        if (ex.RequestInformation.HttpStatusCode == (int)HttpStatusCode.PreconditionFailed)
        {
            Console.WriteLine(@"Precondition failure as expected.
                                Blob's ETag does not match.");
        }
        else
        {
            throw;
        }
    }
    Console.WriteLine();
}

Blob 的封閉式並行存取

程式碼範例：

public void DemonstratePessimisticConcurrencyBlob(string containerName, string blobName)
{
    Console.WriteLine("Demonstrate pessimistic concurrency");

    // Parse connection string and create container.
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConnectionString);
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
    CloudBlobContainer container = blobClient.GetContainerReference(containerName);
    container.CreateIfNotExists();

    CloudBlockBlob blockBlob = container.GetBlockBlobReference(blobName);
    blockBlob.UploadText("Hello World!");
    Console.WriteLine("Blob added.");

    // Acquire lease for 15 seconds.
    string lease = blockBlob.AcquireLease(TimeSpan.FromSeconds(15), null);
    Console.WriteLine("Blob lease acquired. Lease = {0}", lease);

    // Update blob using lease. This operation should succeed.
    const string helloText = "Blob updated";
    var accessCondition = AccessCondition.GenerateLeaseCondition(lease);
    blockBlob.UploadText(helloText, accessCondition: accessCondition);
    Console.WriteLine("Blob updated using an exclusive lease");

    // Simulate another client attempting to update to blob without providing lease.
    try
    {
        // Operation will fail as no valid lease was provided.
        Console.WriteLine("Now try to update blob without valid lease.");
        blockBlob.UploadText("Update operation will fail without lease.");
    }
    catch (StorageException ex)
    {
        if (ex.RequestInformation.HttpStatusCode == (int)HttpStatusCode.PreconditionFailed)
        {
            Console.WriteLine(@"Precondition failure error as expected.
                                Blob lease not provided.");
        }
        else
        {
            throw;
        }
    }

    // Release lease proactively.
    blockBlob.ReleaseLease(accessCondition);
    Console.WriteLine();
}

使用 Blob 記憶體建置高可用性應用程式

下載範例專案、解壓縮 (解壓縮) storage-dotnet-circuit-breaker-pattern-ha-apps-using-ra-grs.zip 檔案，然後流覽至 v11 資料夾以尋找項目檔。

您也可以使用 git 將應用程式的複本下載到您的開發環境。 v11 資料夾中的範例專案包含主控台應用程式。

git clone https://github.com/Azure-Samples/storage-dotnet-circuit-breaker-pattern-ha-apps-using-ra-grs.git

設定範例

在應用程式，您必須提供儲存體帳戶的連接字串。您可以在執行應用程式的本機電腦上，將此連接字串儲存在環境變數內。請根據您的作業系統，遵循以下其中一個範例來建立環境變數。

在 Azure 入口網站中，瀏覽至您的儲存體帳戶。在儲存體帳戶中選取 [設定] 下的 [存取金鑰]。從主要或次要金鑰複製連接字串。根據您的作業系統執行下列其中一個命令，將 <yourconnectionstring> 取代為實際的連接字串。此命令會將一個環境變數儲存至本機電腦。在 Windows 中，必須重新載入命令提示字元或您所使用的殼層，才能使用此環境變數。

執行主控台應用程式

在 Visual Studio 中，按下 F5 或選取 [啟動]，開始對應用程式進行偵錯。若已設定套件還原，Visual Studio 會自動還原缺少的 NuGet 套件，如需深入了解，請造訪透過套件還原來安裝和解除安裝套件。

隨即會有主控台視窗啟動，應用程式也會開始執行。此應用程式會將 HelloWorld.png 影像從解決方案上傳到儲存體帳戶。此應用程式會進行檢查，以確定影像已複寫至次要 RA-GZRS 端點。之後，則會開始下載影像，最多會下載 999 次。每次的讀取都會以 P 或 S 來表示。其中，P 代表主要端點，S 則代表次要端點。

在程式碼範例中，系統會使用 Program.cs 檔案中的 RunCircuitBreakerAsync 工作，透過 DownloadToFileAsync 方法從儲存體帳戶下載影像。在下載之前，系統會先定義 OperationContext。作業內容會定義事件處理常式，當下載作業成功完成，或下載作業失敗而正在重試時，便會引發這些處理常式。

了解範例程式碼

重試事件處理常式

當影像下載失敗，並設定為重試時，便會呼叫 OperationContextRetrying 事件處理常式。如果達到應用程式中定義的重試次數上限，該項要求的 LocationMode 就會變更為 SecondaryOnly。這項設定會迫使應用程式嘗試從次要端點下載影像。因為不會無限期地重試主要端點，這項設定可減少要求該影像所花費的時間。

private static void OperationContextRetrying(object sender, RequestEventArgs e)
{
    retryCount++;
    Console.WriteLine("Retrying event because of failure reading the primary. RetryCount = " + retryCount);

    // Check if we have had more than n retries in which case switch to secondary.
    if (retryCount >= retryThreshold)
    {

        // Check to see if we can fail over to secondary.
        if (blobClient.DefaultRequestOptions.LocationMode != LocationMode.SecondaryOnly)
        {
            blobClient.DefaultRequestOptions.LocationMode = LocationMode.SecondaryOnly;
            retryCount = 0;
        }
        else
        {
            throw new ApplicationException("Both primary and secondary are unreachable. Check your application's network connection. ");
        }
    }
}

要求已完成的事件處理常式

當影像下載成功時，便會呼叫 OperationContextRequestCompleted 事件處理常式。如果應用程式使用次要端點，則應用程式會繼續使用此端點，但最多 20 次。 20 次後，應用程式就會將 LocationMode 重設為 PrimaryThenSecondary，並重試主要端點。如果要求成功，應用程式會繼續從主要端點讀取。

private static void OperationContextRequestCompleted(object sender, RequestEventArgs e)
{
    if (blobClient.DefaultRequestOptions.LocationMode == LocationMode.SecondaryOnly)
    {
        // You're reading the secondary. Let it read the secondary [secondaryThreshold] times,
        //    then switch back to the primary and see if it's available now.
        secondaryReadCount++;
        if (secondaryReadCount >= secondaryThreshold)
        {
            blobClient.DefaultRequestOptions.LocationMode = LocationMode.PrimaryThenSecondary;
            secondaryReadCount = 0;
        }
    }
}

將大量隨機數據上傳至 Azure 記憶體

執行緒的最小和最大數目會設定為 100，以確保能允許大量的並行連線。

private static async Task UploadFilesAsync()
{
    // Create five randomly named containers to store the uploaded files.
    CloudBlobContainer[] containers = await GetRandomContainersAsync();

    var currentdir = System.IO.Directory.GetCurrentDirectory();

    // Path to the directory to upload
    string uploadPath = currentdir + "\\upload";

    // Start a timer to measure how long it takes to upload all the files.
    Stopwatch time = Stopwatch.StartNew();

    try
    {
        Console.WriteLine("Iterating in directory: {0}", uploadPath);

        int count = 0;
        int max_outstanding = 100;
        int completed_count = 0;

        // Define the BlobRequestOptions on the upload.
        // This includes defining an exponential retry policy to ensure that failed connections
        // are retried with a back off policy. As multiple large files are being uploaded using
        // large block sizes, this can cause an issue if an exponential retry policy is not defined.
        // Additionally, parallel operations are enabled with a thread count of 8.
        // This should be a multiple of the number of processor cores in the machine.
        // Lastly, MD5 hash validation is disabled for this example, improving the upload speed.
        BlobRequestOptions options = new BlobRequestOptions
        {
            ParallelOperationThreadCount = 8,
            DisableContentMD5Validation = true,
            StoreBlobContentMD5 = false
        };

        // Create a new instance of the SemaphoreSlim class to 
        // define the number of threads to use in the application.
        SemaphoreSlim sem = new SemaphoreSlim(max_outstanding, max_outstanding);

        List<Task> tasks = new List<Task>();
        Console.WriteLine("Found {0} file(s)", Directory.GetFiles(uploadPath).Count());

        // Iterate through the files
        foreach (string path in Directory.GetFiles(uploadPath))
        {
            var container = containers[count % 5];
            string fileName = Path.GetFileName(path);
            Console.WriteLine("Uploading {0} to container {1}", path, container.Name);
            CloudBlockBlob blockBlob = container.GetBlockBlobReference(fileName);

            // Set the block size to 100MB.
            blockBlob.StreamWriteSizeInBytes = 100 * 1024 * 1024;

            await sem.WaitAsync();

            // Create a task for each file to upload. The tasks are
            // added to a collection and all run asynchronously.
            tasks.Add(blockBlob.UploadFromFileAsync(path, null, options, null).ContinueWith((t) =>
            {
                sem.Release();
                Interlocked.Increment(ref completed_count);
            }));

            count++;
        }

        // Run all the tasks asynchronously.
        await Task.WhenAll(tasks);

        time.Stop();

        Console.WriteLine("Upload has been completed in {0} seconds. Press any key to continue", time.Elapsed.TotalSeconds.ToString());

        Console.ReadLine();
    }
    catch (DirectoryNotFoundException ex)
    {
        Console.WriteLine("Error parsing files in the directory: {0}", ex.Message);
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
}

除了設定執行緒和連線限制設定，UploadFromStreamAsync 的 BlobRequestOptions 方法也會設定為使用平行處理原則，並停用 MD5 雜湊驗證。檔案會以 100 MB 的區塊上傳，這項設定可提供更佳的效能，但如果使用效能差的網路則可能提高成本，因為整個 100 MB 的區塊可能會因為失敗而需要重試。

屬性	值	描述
ParallelOperationThreadCount	8	上傳時，此設定會將 Blob 分成區塊。為達到最高效能，此值應為核心數目的 8 倍。
DisableContentMD5Validation	true	此屬性可停用檢查上傳內容的 MD5 雜湊。停用 MD5 驗證可獲得較快的傳輸速度。但不會確認所傳輸檔案的有效性和完整性。
StoreBlobContentMD5	false	此屬性可判斷是否已計算及儲存檔案的 MD5 雜湊。
RetryPolicy	具有 2 秒的輪詢，最多重試 10 次	決定要求的重試原則。連線失敗時進行重試，在此範例中，ExponentialRetry 原則設定為具有 2 秒的輪詢，以及最多重試 10 次。當您的應用程式快達到 Blob 儲存體的延展性目標時，此設定就十分重要。如需詳細資訊，請參閱 Blob 儲存體的延展性和效能目標。

從 Azure 儲存體下載大量隨機資料

應用程式會讀取 storageconnectionstring中指定之儲存體帳戶內的容器。其會使用容器中的 ListBlobsSegmented 方法逐次查看 10 個 Blob，並使用 ListBlobsSegmentedAsync 方法將 Blob 下載到本機電腦。

下表顯示下載每個 Blob 時所定義的 BlobRequestOptions。

屬性	值	描述
DisableContentMD5Validation	true	此屬性可停用檢查上傳內容的 MD5 雜湊。停用 MD5 驗證可獲得較快的傳輸速度。但不會確認所傳輸檔案的有效性和完整性。
StoreBlobContentMD5	false	此屬性可判斷是否已計算及儲存 MD5 雜湊。

private static async Task DownloadFilesAsync()
{
    CloudBlobClient blobClient = GetCloudBlobClient();

    // Define the BlobRequestOptions on the download, including disabling MD5 
    // hash validation for this example, this improves the download speed.
    BlobRequestOptions options = new BlobRequestOptions
    {
        DisableContentMD5Validation = true,
        StoreBlobContentMD5 = false
    };

    // Retrieve the list of containers in the storage account.
    // Create a directory and configure variables for use later.
    BlobContinuationToken continuationToken = null;
    List<CloudBlobContainer> containers = new List<CloudBlobContainer>();
    do
    {
        var listingResult = await blobClient.ListContainersSegmentedAsync(continuationToken);
        continuationToken = listingResult.ContinuationToken;
        containers.AddRange(listingResult.Results);
    }
    while (continuationToken != null);

    var directory = Directory.CreateDirectory("download");
    BlobResultSegment resultSegment = null;
    Stopwatch time = Stopwatch.StartNew();

    // Download the blobs
    try
    {
        List<Task> tasks = new List<Task>();
        int max_outstanding = 100;
        int completed_count = 0;

        // Create a new instance of the SemaphoreSlim class to
        // define the number of threads to use in the application.
        SemaphoreSlim sem = new SemaphoreSlim(max_outstanding, max_outstanding);

        // Iterate through the containers
        foreach (CloudBlobContainer container in containers)
        {
            do
            {
                // Return the blobs from the container, 10 at a time.
                resultSegment = await container.ListBlobsSegmentedAsync(null, true, BlobListingDetails.All, 10, continuationToken, null, null);
                continuationToken = resultSegment.ContinuationToken;
                {
                    foreach (var blobItem in resultSegment.Results)
                    {

                        if (((CloudBlob)blobItem).Properties.BlobType == BlobType.BlockBlob)
                        {
                            // Get the blob and add a task to download the blob asynchronously from the storage account.
                            CloudBlockBlob blockBlob = container.GetBlockBlobReference(((CloudBlockBlob)blobItem).Name);
                            Console.WriteLine("Downloading {0} from container {1}", blockBlob.Name, container.Name);
                            await sem.WaitAsync();
                            tasks.Add(blockBlob.DownloadToFileAsync(directory.FullName + "\\" + blockBlob.Name, FileMode.Create, null, options, null).ContinueWith((t) =>
                            {
                                sem.Release();
                                Interlocked.Increment(ref completed_count);
                            }));

                        }
                    }
                }
            }
            while (continuationToken != null);
        }

        // Creates an asynchronous task that completes when all the downloads complete.
        await Task.WhenAll(tasks);
    }
    catch (Exception e)
    {
        Console.WriteLine("\nError encountered during transfer: {0}", e.Message);
    }

    time.Stop();
    Console.WriteLine("Download has been completed in {0} seconds. Press any key to continue", time.Elapsed.TotalSeconds.ToString());
    Console.ReadLine();
}

(傳統) 啟用 Azure 儲存體分析記錄

程式碼範例：

var storageAccount = CloudStorageAccount.Parse(connStr);  
var queueClient = storageAccount.CreateCloudQueueClient();  
var serviceProperties = queueClient.GetServiceProperties();

serviceProperties.Logging.LoggingOperations = LoggingOperations.All;  
serviceProperties.Logging.RetentionDays = 2;

queueClient.SetServiceProperties(serviceProperties);

修改記錄資料保留期間

下列範例會將 Blob 和佇列儲存體服務的保留期間列印到主控台。

var storageAccount = CloudStorageAccount.Parse(connectionString);

var blobClient = storageAccount.CreateCloudBlobClient();
var queueClient = storageAccount.CreateCloudQueueClient();

var blobserviceProperties = blobClient.GetServiceProperties();
var queueserviceProperties = queueClient.GetServiceProperties();

Console.WriteLine("Retention period for logs from the blob service is: " +
   blobserviceProperties.Logging.RetentionDays.ToString());

Console.WriteLine("Retention period for logs from the queue service is: " +
   queueserviceProperties.Logging.RetentionDays.ToString());

下列範例會將 Blob 和佇列儲存體服務記錄的保留期限變更為 4 天。


blobserviceProperties.Logging.RetentionDays = 4;
queueserviceProperties.Logging.RetentionDays = 4;

blobClient.SetServiceProperties(blobserviceProperties);
queueClient.SetServiceProperties(queueserviceProperties);

(傳統) 啟用 Azure 儲存體分析計量

程式碼範例：

var storageAccount = CloudStorageAccount.Parse(connStr);  
var queueClient = storageAccount.CreateCloudQueueClient();  
var serviceProperties = queueClient.GetServiceProperties();

serviceProperties.HourMetrics.MetricsLevel = MetricsLevel.Service;  
serviceProperties.HourMetrics.RetentionDays = 10;

queueClient.SetServiceProperties(serviceProperties);

針對用戶端應用程式設定傳輸層安全性 (TLS)

下列範例示範如何使用 Azure 記憶體用戶端連結庫 11.x 版在 .NET 用戶端中啟用 TLS 1.2：

static void EnableTls12()
{
    // Enable TLS 1.2 before connecting to Azure Storage
    System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12;

    // Add your connection string here.
    string connectionString = "";

    // Connect to Azure Storage and create a new container.
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

    CloudBlobContainer container = blobClient.GetContainerReference("sample-container");
    container.CreateIfNotExists();
}

監視、診斷與疑難排解 Microsoft Azure 儲存體 (傳統)

如果儲存體用戶端程式庫在用戶端擲回 StorageException，則 RequestInformation 屬性所包含的 RequestResult 物件裡會出現 ServiceRequestID 屬性。您可以從 OperationContext 執行個體存取 RequestResult 物件。

下列程式碼範例示範如何藉由附加 OperationContext 物件要求至儲存體服務來設定自訂的 ClientRequestId 值。此範例同時示範如何從回應訊息擷取 ServerRequestId 值。

//Parse the connection string for the storage account.
const string ConnectionString = "DefaultEndpointsProtocol=https;AccountName=account-name;AccountKey=account-key";
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConnectionString);
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

// Create an Operation Context that includes custom ClientRequestId string based on constants defined within the application along with a Guid.
OperationContext oc = new OperationContext();
oc.ClientRequestID = String.Format("{0} {1} {2} {3}", HOSTNAME, APPNAME, USERID, Guid.NewGuid().ToString());

try
{
    CloudBlobContainer container = blobClient.GetContainerReference("democontainer");
    ICloudBlob blob = container.GetBlobReferenceFromServer("testImage.jpg", null, null, oc);  
    var downloadToPath = string.Format("./{0}", blob.Name);
    using (var fs = File.OpenWrite(downloadToPath))
    {
        blob.DownloadToStream(fs, null, null, oc);
        Console.WriteLine("\t Blob downloaded to file: {0}", downloadToPath);
    }
}
catch (StorageException storageException)
{
    Console.WriteLine("Storage exception {0} occurred", storageException.Message);
    // Multiple results may exist due to client side retry logic - each retried operation will have a unique ServiceRequestId
    foreach (var result in oc.RequestResults)
    {
            Console.WriteLine("HttpStatus: {0}, ServiceRequestId {1}", result.HttpStatusCode, result.ServiceRequestID);
    }
}

調查用戶端效能問題 - 停用 Nagle 演算法

程式碼範例：

var storageAccount = CloudStorageAccount.Parse(connStr);
ServicePoint queueServicePoint = ServicePointManager.FindServicePoint(storageAccount.QueueEndpoint);
queueServicePoint.UseNagleAlgorithm = false;

程式碼範例：

CloudBlobClient client = new CloudBlobClient(blobEndpoint, new StorageCredentials(accountName, accountKey));
// Set the service properties.
ServiceProperties sp = client.GetServiceProperties();
sp.DefaultServiceVersion = "2013-08-15";
CorsRule cr = new CorsRule();
cr.AllowedHeaders.Add("*");
cr.AllowedMethods = CorsHttpMethods.Get | CorsHttpMethods.Put;
cr.AllowedOrigins.Add("http://www.contoso.com");
cr.ExposedHeaders.Add("x-ms-*");
cr.MaxAgeInSeconds = 5;
sp.Cors.CorsRules.Clear();
sp.Cors.CorsRules.Add(cr);
client.SetServiceProperties(sp);

建立指定大小的空分頁 Blob

若要建立分頁 Blob，首先需建立 CloudBlobClient 物件，搭配用來存取您儲存體帳戶 (圖 1 中的 pbaccount) 之 Blob 儲存體的基底 URI，以及 StorageCredentialsAccountAndKey 物件，如下列範例所示。然後，此範例會建立 CloudBlobContainer 物件的參照，然後建立容器 (testvhds) (如果它尚未存在)。然後，透過 CloudBlobContainer 物件，建立 CloudPageBlob 物件的參照，方法是指定要存取的分頁 Blob 名稱 (os4.vhd)。若要建立分頁 Blob，請呼叫 CloudPageBlob.Create 傳入要建立之 Blob 的大小上限。 blobSize 必須是 512 位元組的倍數。

using Microsoft.Azure;
using Microsoft.Azure.Storage;
using Microsoft.Azure.Storage.Blob;

long OneGigabyteAsBytes = 1024 * 1024 * 1024;
// Retrieve storage account from connection string.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
    CloudConfigurationManager.GetSetting("StorageConnectionString"));

// Create the blob client.
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

// Retrieve a reference to a container.
CloudBlobContainer container = blobClient.GetContainerReference("testvhds");

// Create the container if it doesn't already exist.
container.CreateIfNotExists();

CloudPageBlob pageBlob = container.GetPageBlobReference("os4.vhd");
pageBlob.Create(16 * OneGigabyteAsBytes);

調整分頁 Blob 大小

若要在建立之後重新調整分頁 Blob 的大小，請使用調整大小方法。要求的大小應該是 512 位元組的倍數。

pageBlob.Resize(32 * OneGigabyteAsBytes);

將分頁寫入分頁 Blob

若要寫入分頁，請使用 CloudPageBlob.WritePages 方法。

pageBlob.WritePages(dataStream, startingOffset);

從分頁 Blob 讀取分頁

若要讀取分頁，請使用 CloudPageBlob.DownloadRangeToByteArray 方法，從分頁 Blob 讀取位元組範圍。

byte[] buffer = new byte[rangeSize];
pageBlob.DownloadRangeToByteArray(buffer, bufferOffset, pageBlobOffset, rangeSize);

若要判斷有哪些分頁是由資料所支援，請使用 CloudPageBlob.GetPageRanges。然後，您可以對傳回的範圍進行列舉，並下載每個範圍中的資料。

IEnumerable<PageRange> pageRanges = pageBlob.GetPageRanges();

foreach (PageRange range in pageRanges)
{
    // Calculate the range size
    int rangeSize = (int)(range.EndOffset + 1 - range.StartOffset);

    byte[] buffer = new byte[rangeSize];

    // Read from the correct starting offset in the page blob and
    // place the data in the bufferOffset of the buffer byte array
    pageBlob.DownloadRangeToByteArray(buffer, bufferOffset, range.StartOffset, rangeSize);

    // Then use the buffer for the page range just read
}

分享方式：

使用 .NET 11.x 版用戶端連結庫 Azure Blob 儲存體程式代碼範例

建立快照集

刪除快照集

建立預存的存取原則

建立容器或 blob 的服務 SAS

建立 blob 的服務 SAS

建立帳戶 SAS

從用戶端使用帳戶 SAS

Blob 的開放式並行存取

Blob 的封閉式並行存取

使用 Blob 記憶體建置高可用性應用程式

設定範例

執行主控台應用程式

了解範例程式碼

重試事件處理常式

要求已完成的事件處理常式

將大量隨機數據上傳至 Azure 記憶體

從 Azure 儲存體下載大量隨機資料

(傳統) 啟用 Azure 儲存體分析記錄

修改記錄資料保留期間

(傳統) 啟用 Azure 儲存體分析計量

針對用戶端應用程式設定傳輸層安全性 (TLS)

監視、診斷與疑難排解 Microsoft Azure 儲存體 (傳統)

調查用戶端效能問題 - 停用 Nagle 演算法

建立指定大小的空分頁 Blob

調整分頁 Blob 大小

將分頁寫入分頁 Blob

從分頁 Blob 讀取分頁

更多資源

分享方式：

使用 .NET 11.x 版用戶端連結庫 Azure Blob 儲存體 程式代碼範例

建立快照集

刪除快照集

建立預存的存取原則

建立容器或 blob 的服務 SAS

建立 blob 的服務 SAS

建立帳戶 SAS

從用戶端使用帳戶 SAS

Blob 的開放式並行存取

Blob 的封閉式並行存取

使用 Blob 記憶體建置高可用性應用程式

設定範例

執行主控台應用程式

了解範例程式碼

重試事件處理常式

要求已完成的事件處理常式

將大量隨機數據上傳至 Azure 記憶體

從 Azure 儲存體下載大量隨機資料

(傳統) 啟用 Azure 儲存體分析 記錄

修改記錄資料保留期間

(傳統) 啟用 Azure 儲存體分析 計量

針對用戶端應用程式設定傳輸層安全性 (TLS)

監視、診斷與疑難排解 Microsoft Azure 儲存體 (傳統)

調查用戶端效能問題 - 停用 Nagle 演算法

調查網路等待時間問題 - 設定跨原始來源資源分享 (CORS)

建立指定大小的空分頁 Blob

調整分頁 Blob 大小

將分頁寫入分頁 Blob

從分頁 Blob 讀取分頁

更多資源

使用 .NET 11.x 版用戶端連結庫 Azure Blob 儲存體程式代碼範例

(傳統) 啟用 Azure 儲存體分析記錄

(傳統) 啟用 Azure 儲存體分析計量