glglak

 private   async Task<string> UploadBlobStorage(IFormFile filepayupload)
        {
            string url = string.Empty;
            if (filepayupload != null)
            {

                using (var stream = new MemoryStream())
                {
                    await filepayupload.CopyToAsync(stream);
                    var streamArray = stream.ToArray();

glglak

 public  async  Task<byte[]> GetImageAsByteArray(string imageFilePath)
        {
            CloudStorageAccount cloudStorageAccount = CloudStorageAccount.Parse(connectionStorage);
            CloudBlobClient cloudBlobClient = cloudStorageAccount.CreateCloudBlobClient();
            CloudBlobContainer cloudBlobContainer = cloudBlobClient.GetContainerReference (containerReferrence);
            CloudBlob cloudBlob = cloudBlobContainer.GetBlobReference(new CloudBlockBlob(new Uri(imageFilePath)).Name);
      
             await  cloudBlob.FetchAttributesAsync();
            long fileByteLength = cloudBlob.Properties.Length;
            Byte[] myByteArray = new Byte[fileByteLength];

glglak

Install-Package WindowsAzure.Storage -Version 9.2.0