c# Copy an Azure Storage blob into Subfolder or Subdirectories

 Copying All Blob of given Container into the same container and under subfolder?

Here are few key points about the copying blob in Azure Storage Account:

• When you copy a blob within the same storage account, it's a synchronous operation.
•  When you copy across accounts it's an asynchronous operation.
• The source blob for a copy operation may be a block blob, an append blob, a page blob, or a snapshot. If the destination blob already exists, it must be of the same blob type as the source blob. An existing destination blob will be overwritten.
• The destination blob can't be modified while a copy operation is in progress. A destination blob can only have one outstanding copy operation. In other words, a blob can't be the destination for multiple pending copy operations.

To copy a blob, call one of the following methods:

• StartCopyFromUri
• StartCopyFromUriAsync

We are using  .Net Core 3.1

Step  1:  Install-Package Azure.Storage.Blobs -Version 12.10.0

Step 2:  use the following code to move your container (named images)file into the same container  under a subfolder name called 

for example, if your current file store in images/my-pic.png this code will move to images/my-folder/my-pic.png

private static async Task CopyBlobToSubFolderAsync(BlobContainerClient container)

{

    

        // Get the name of the first blob in the container to use as the source.

        string blobName = container.GetBlobs().FirstOrDefault().Name;

        // Create a BlobClient representing the source blob to copy.

        BlobClient sourceBlob = container.GetBlobClient(blobName);

        // Ensure that the source blob exists.

        if (await sourceBlob.ExistsAsync())

        {

            // Lease the source blob for the copy operation 

            // to prevent another client from modifying it.

            BlobLeaseClient lease = sourceBlob.GetBlobLeaseClient();

            // Specifying -1 for the lease interval creates an infinite lease.

            await lease.AcquireAsync(TimeSpan.FromSeconds(-1));

            // Get the source blob's properties and display the lease state.

            BlobProperties sourceProperties = await sourceBlob.GetPropertiesAsync();

            // Get a BlobClient representing the destination blob with a unique name.

            BlobClient destBlob = 

                container.GetBlobClient("my-folder/" + sourceBlob.Name);

            // Start the copy operation.

            await destBlob.StartCopyFromUriAsync(sourceBlob.Uri);

            // Get the destination blob's properties and display the copy status.

            BlobProperties destProperties = await destBlob.GetPropertiesAsync();

         

            // Update the source blob's properties.

            sourceProperties = await sourceBlob.GetPropertiesAsync();

            if (sourceProperties.LeaseState == LeaseState.Leased)

            {

                // Break the lease on the source blob.

                await lease.BreakAsync();

                // Update the source blob's properties to check the lease state.

                sourceProperties = await sourceBlob.GetPropertiesAsync();

            }

        }   

}