use this below code :
CloudBlockBlob blockBlob = container.GetBlockBlobReference("photo1.jpg");
if not then list out the content loop over it to find u r relevant file name !
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
CloudConfigurationManager.GetSetting("StorageConnectionString"));
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
CloudBlobContainer container = blobClient.GetContainerReference("photos");
foreach (IListBlobItem item in container.ListBlobs(null, false))
{
if (item.GetType() == typeof(CloudBlockBlob))
{
CloudBlockBlob blob = (CloudBlockBlob)item;
Console.WriteLine("Block blob of length {0}: {1}", blob.Properties.Length, blob.Uri);
}
else if (item.GetType() == typeof(CloudPageBlob))
{
CloudPageBlob pageBlob = (CloudPageBlob)item;
Console.WriteLine("Page blob of length {0}: {1}", pageBlob.Properties.Length, pageBlob.Uri);
}
else if (item.GetType() == typeof(CloudBlobDirectory))
{
CloudBlobDirectory directory = (CloudBlobDirectory)item;
Console.WriteLine("Directory: {0}", directory.Uri);
}
}