Azure File Share code samples using .NET version 11.x client libraries

Article
05/05/2023

This article shows code samples that use version 11.x of the Azure File Share client library for .NET.

On March 31, 2023, we retired support for Azure SDK libraries which do not conform to the current Azure SDK guidelines. The new Azure SDK libraries are updated regularly to drive consistent experiences and strengthen your security posture. It's recommended that you transition to the new Azure SDK libraries to take advantage of the new capabilities and critical security updates.

Although the older libraries can still be used beyond March 31, 2023, they'll no longer receive official support and updates from Microsoft. For more information, see the support retirement announcement.

Prerequisites

Install these packages in your project directory:

Microsoft.Azure.Storage.Common
Microsoft.Azure.Storage.File
Microsoft.Azure.ConfigurationManager

Add the following using directives:

using Microsoft.Azure;              // Namespace for Azure Configuration Manager
using Microsoft.Azure.Storage;      // Namespace for Storage Client Library
using Microsoft.Azure.Storage.Blob; // Namespace for Azure Blobs
using Microsoft.Azure.Storage.File; // Namespace for Azure Files

Related article: Develop for Azure Files with .NET

Add the following code to access the file share:

// Create a CloudFileClient object for credentialed access to Azure Files.
CloudFileClient fileClient = storageAccount.CreateCloudFileClient();

// Get a reference to the file share we created previously.
CloudFileShare share = fileClient.GetShareReference("logs");

// Ensure that the share exists.
if (share.Exists())
{
    // Get a reference to the root directory for the share.
    CloudFileDirectory rootDir = share.GetRootDirectoryReference();

    // Get a reference to the directory we created previously.
    CloudFileDirectory sampleDir = rootDir.GetDirectoryReference("CustomLogs");

    // Ensure that the directory exists.
    if (sampleDir.Exists())
    {
        // Get a reference to the file we created previously.
        CloudFile file = sampleDir.GetFileReference("Log1.txt");

        // Ensure that the file exists.
        if (file.Exists())
        {
            // Write the contents of the file to the console window.
            Console.WriteLine(file.DownloadTextAsync().Result);
        }
    }
}

Related article: Develop for Azure Files with .NET

Beginning with version 5.x of the Azure Files client library, you can set the quota (maximum size) for a file share. You can also check to see how much data is currently stored on the share.

Setting the quota for a share limits the total size of the files stored on the share. If the total size of files on the share exceeds the quota, clients can't increase the size of existing files. Clients also can't create new files, unless those files are empty.

The example below shows how to check the current usage for a share and how to set the quota for the share.

// Parse the connection string for the storage account.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
    Microsoft.Azure.CloudConfigurationManager.GetSetting("StorageConnectionString"));

// Create a CloudFileClient object for credentialed access to Azure Files.
CloudFileClient fileClient = storageAccount.CreateCloudFileClient();

// Get a reference to the file share we created previously.
CloudFileShare share = fileClient.GetShareReference("logs");

// Ensure that the share exists.
if (share.Exists())
{
    // Check current usage stats for the share.
    // Note that the ShareStats object is part of the protocol layer for the File service.
    Microsoft.Azure.Storage.File.Protocol.ShareStats stats = share.GetStats();
    Console.WriteLine("Current share usage: {0} GiB", stats.Usage.ToString());

    // Specify the maximum size of the share, in GiB.
    // This line sets the quota to be 10 GiB greater than the current usage of the share.
    share.Properties.Quota = 10 + stats.Usage;
    share.SetProperties();

    // Now check the quota for the share. Call FetchAttributes() to populate the share's properties.
    share.FetchAttributes();
    Console.WriteLine("Current share quota: {0} GiB", share.Properties.Quota);
}

Beginning with version 5.x of the Azure Files client library, you can generate a shared access signature (SAS) for a file share or for an individual file.

You can also create a stored access policy on a file share to manage shared access signatures. We recommend creating a stored access policy because it lets you revoke the SAS if it becomes compromised. The following example creates a stored access policy on a share. The example uses that policy to provide the constraints for a SAS on a file in the share.

// Parse the connection string for the storage account.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
    Microsoft.Azure.CloudConfigurationManager.GetSetting("StorageConnectionString"));

// Create a CloudFileClient object for credentialed access to Azure Files.
CloudFileClient fileClient = storageAccount.CreateCloudFileClient();

// Get a reference to the file share we created previously.
CloudFileShare share = fileClient.GetShareReference("logs");

// Ensure that the share exists.
if (share.Exists())
{
    string policyName = "sampleSharePolicy" + DateTime.UtcNow.Ticks;

    // Create a new stored access policy and define its constraints.
    SharedAccessFilePolicy sharedPolicy = new SharedAccessFilePolicy()
        {
            SharedAccessExpiryTime = DateTime.UtcNow.AddHours(24),
            Permissions = SharedAccessFilePermissions.Read | SharedAccessFilePermissions.Write
        };

    // Get existing permissions for the share.
    FileSharePermissions permissions = share.GetPermissions();

    // Add the stored access policy to the share's policies. Note that each policy must have a unique name.
    permissions.SharedAccessPolicies.Add(policyName, sharedPolicy);
    share.SetPermissions(permissions);

    // Generate a SAS for a file in the share and associate this access policy with it.
    CloudFileDirectory rootDir = share.GetRootDirectoryReference();
    CloudFileDirectory sampleDir = rootDir.GetDirectoryReference("CustomLogs");
    CloudFile file = sampleDir.GetFileReference("Log1.txt");
    string sasToken = file.GetSharedAccessSignature(null, policyName);
    Uri fileSasUri = new Uri(file.StorageUri.PrimaryUri.ToString() + sasToken);

    // Create a new CloudFile object from the SAS, and write some text to the file.
    CloudFile fileSas = new CloudFile(fileSasUri);
    fileSas.UploadText("This write operation is authorized via SAS.");
    Console.WriteLine(fileSas.DownloadText());
}

Copy files

Related article: Develop for Azure Files with .NET

Beginning with version 5.x of the Azure Files client library, you can copy a file to another file, a file to a blob, or a blob to a file.

You can also use AzCopy to copy one file to another or to copy a blob to a file or the other way around. See Get started with AzCopy.

Note

If you are copying a blob to a file, or a file to a blob, you must use a shared access signature (SAS) to authorize access to the source object, even if you are copying within the same storage account.

Copy a file to another file

The following example copies a file to another file in the same share. You can use Shared Key authentication to do the copy because this operation copies files within the same storage account.

// Parse the connection string for the storage account.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
    Microsoft.Azure.CloudConfigurationManager.GetSetting("StorageConnectionString"));

// Create a CloudFileClient object for credentialed access to Azure Files.
CloudFileClient fileClient = storageAccount.CreateCloudFileClient();

// Get a reference to the file share we created previously.
CloudFileShare share = fileClient.GetShareReference("logs");

// Ensure that the share exists.
if (share.Exists())
{
    // Get a reference to the root directory for the share.
    CloudFileDirectory rootDir = share.GetRootDirectoryReference();

    // Get a reference to the directory we created previously.
    CloudFileDirectory sampleDir = rootDir.GetDirectoryReference("CustomLogs");

    // Ensure that the directory exists.
    if (sampleDir.Exists())
    {
        // Get a reference to the file we created previously.
        CloudFile sourceFile = sampleDir.GetFileReference("Log1.txt");

        // Ensure that the source file exists.
        if (sourceFile.Exists())
        {
            // Get a reference to the destination file.
            CloudFile destFile = sampleDir.GetFileReference("Log1Copy.txt");

            // Start the copy operation.
            destFile.StartCopy(sourceFile);

            // Write the contents of the destination file to the console window.
            Console.WriteLine(destFile.DownloadText());
        }
    }
}

Copy a file to a blob

The following example creates a file and copies it to a blob within the same storage account. The example creates a SAS for the source file, which the service uses to authorize access to the source file during the copy operation.

// Parse the connection string for the storage account.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
    Microsoft.Azure.CloudConfigurationManager.GetSetting("StorageConnectionString"));

// Create a CloudFileClient object for credentialed access to Azure Files.
CloudFileClient fileClient = storageAccount.CreateCloudFileClient();

// Create a new file share, if it does not already exist.
CloudFileShare share = fileClient.GetShareReference("sample-share");
share.CreateIfNotExists();

// Create a new file in the root directory.
CloudFile sourceFile = share.GetRootDirectoryReference().GetFileReference("sample-file.txt");
sourceFile.UploadText("A sample file in the root directory.");

// Get a reference to the blob to which the file will be copied.
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
CloudBlobContainer container = blobClient.GetContainerReference("sample-container");
container.CreateIfNotExists();
CloudBlockBlob destBlob = container.GetBlockBlobReference("sample-blob.txt");

// Create a SAS for the file that's valid for 24 hours.
// Note that when you are copying a file to a blob, or a blob to a file, you must use a SAS
// to authorize access to the source object, even if you are copying within the same
// storage account.
string fileSas = sourceFile.GetSharedAccessSignature(new SharedAccessFilePolicy()
{
    // Only read permissions are required for the source file.
    Permissions = SharedAccessFilePermissions.Read,
    SharedAccessExpiryTime = DateTime.UtcNow.AddHours(24)
});

// Construct the URI to the source file, including the SAS token.
Uri fileSasUri = new Uri(sourceFile.StorageUri.PrimaryUri.ToString() + fileSas);

// Copy the file to the blob.
destBlob.StartCopy(fileSasUri);

// Write the contents of the file to the console window.
Console.WriteLine("Source file contents: {0}", sourceFile.DownloadText());
Console.WriteLine("Destination blob contents: {0}", destBlob.DownloadText());

You can copy a blob to a file in the same way. If the source object is a blob, then create a SAS to authorize access to that blob during the copy operation.

Related article: Develop for Azure Files with .NET

Beginning with version 8.5 of the Azure Files client library, you can create a share snapshot. You can also list or browse share snapshots and delete share snapshots. Once created, share snapshots are read-only.

The following example creates a file share snapshot:

storageAccount = CloudStorageAccount.Parse(ConnectionString); 
fClient = storageAccount.CreateCloudFileClient(); 
string baseShareName = "myazurefileshare"; 
CloudFileShare myShare = fClient.GetShareReference(baseShareName); 
var snapshotShare = myShare.Snapshot();

The following example lists the snapshots on a share:

var shares = fClient.ListShares(baseShareName, ShareListingDetails.All);

The following example browses files and directories within share snapshots:

CloudFileShare mySnapshot = fClient.GetShareReference(baseShareName, snapshotTime); 
var rootDirectory = mySnapshot.GetRootDirectoryReference(); 
var items = rootDirectory.ListFilesAndDirectories();

Taking a snapshot of a file share enables you to recover individual files or the entire file share.

You can restore a file from a file share snapshot by querying the share snapshots of a file share. You can then retrieve a file that belongs to a particular share snapshot. Use that version to directly read or to restore the file.

CloudFileShare liveShare = fClient.GetShareReference(baseShareName);
var rootDirOfliveShare = liveShare.GetRootDirectoryReference();
var dirInliveShare = rootDirOfliveShare.GetDirectoryReference(dirName);
var fileInliveShare = dirInliveShare.GetFileReference(fileName);

CloudFileShare snapshot = fClient.GetShareReference(baseShareName, snapshotTime);
var rootDirOfSnapshot = snapshot.GetRootDirectoryReference();
var dirInSnapshot = rootDirOfSnapshot.GetDirectoryReference(dirName);
var fileInSnapshot = dir1InSnapshot.GetFileReference(fileName);

string sasContainerToken = string.Empty;
SharedAccessFilePolicy sasConstraints = new SharedAccessFilePolicy();
sasConstraints.SharedAccessExpiryTime = DateTime.UtcNow.AddHours(24);
sasConstraints.Permissions = SharedAccessFilePermissions.Read;

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

string sourceUri = (fileInSnapshot.Uri.ToString() + sasContainerToken + "&" + fileInSnapshot.SnapshotTime.ToString()); ;
fileInliveShare.StartCopyAsync(new Uri(sourceUri));

The following example deletes a file share snapshot:

CloudFileShare mySnapshot = fClient.GetShareReference(baseShareName, snapshotTime); mySnapshot.Delete(null, null, null);

Troubleshoot Azure Files by using metrics

Related article: Develop for Azure Files with .NET

Azure Storage Analytics supports metrics for Azure Files. With metrics data, you can trace requests and diagnose issues.

You can enable metrics for Azure Files from the Azure portal. You can also enable metrics programmatically by calling the Set File Service Properties operation with the REST API or one of its analogs in the Azure Files client library.

The following code example shows how to use the .NET client library to enable metrics for Azure Files.

First, add the following using directives to your Program.cs file, along with the ones you added above:

using Microsoft.Azure.Storage.File.Protocol;
using Microsoft.Azure.Storage.Shared.Protocol;

Although Azure Blobs, Azure Tables, and Azure Queues use the shared ServiceProperties type in the Microsoft.Azure.Storage.Shared.Protocol namespace, Azure Files uses its own type, the FileServiceProperties type in the Microsoft.Azure.Storage.File.Protocol namespace. You must reference both namespaces from your code, however, for the following code to compile.

// Parse your storage connection string from your application's configuration file.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
        Microsoft.Azure.CloudConfigurationManager.GetSetting("StorageConnectionString"));
// Create the File service client.
CloudFileClient fileClient = storageAccount.CreateCloudFileClient();

// Set metrics properties for File service.
// Note that the File service currently uses its own service properties type,
// available in the Microsoft.Azure.Storage.File.Protocol namespace.
fileClient.SetServiceProperties(new FileServiceProperties()
{
    // Set hour metrics
    HourMetrics = new MetricsProperties()
    {
        MetricsLevel = MetricsLevel.ServiceAndApi,
        RetentionDays = 14,
        Version = "1.0"
    },
    // Set minute metrics
    MinuteMetrics = new MetricsProperties()
    {
        MetricsLevel = MetricsLevel.ServiceAndApi,
        RetentionDays = 7,
        Version = "1.0"
    }
});

// Read the metrics properties we just set.
FileServiceProperties serviceProperties = fileClient.GetServiceProperties();
Console.WriteLine("Hour metrics:");
Console.WriteLine(serviceProperties.HourMetrics.MetricsLevel);
Console.WriteLine(serviceProperties.HourMetrics.RetentionDays);
Console.WriteLine(serviceProperties.HourMetrics.Version);
Console.WriteLine();
Console.WriteLine("Minute metrics:");
Console.WriteLine(serviceProperties.MinuteMetrics.MetricsLevel);
Console.WriteLine(serviceProperties.MinuteMetrics.RetentionDays);
Console.WriteLine(serviceProperties.MinuteMetrics.Version);

Share via

Prerequisites

Copy files

Copy a file to another file

Copy a file to a blob

Troubleshoot Azure Files by using metrics

Additional resources

Share via

Prerequisites

Access the file share

Set the maximum size for a file share

Generate a shared access signature for a file or file share

Copy files

Copy a file to another file

Copy a file to a blob

Share snapshots

Create share snapshots

List share snapshots

List files and directories within share snapshots

Restore file shares or files from share snapshots

Delete share snapshots

Troubleshoot Azure Files by using metrics

Additional resources