Getting the latest file modified from Azure Blob

       //connection string
        string storageAccount_connectionString = "**NOTE: CONNECTION STRING**";

        // Retrieve storage account from connection string.
        CloudStorageAccount storageAccount = CloudStorageAccount.Parse(storageAccount_connectionString);

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

        // Retrieve reference to a previously created container.
        CloudBlobContainer container = blobClient.GetContainerReference("**NOTE:NAME OF CONTAINER**");
        //The specified container does not exist

        try
        {
            //root directory
            CloudBlobDirectory dira = container.GetDirectoryReference(string.Empty);
            //true for all sub directories else false 
            var rootDirFolders = dira.ListBlobsSegmentedAsync(true, BlobListingDetails.Metadata, null, null, null, null).Result;

            foreach (var blob in rootDirFolders.Results)
            {
                if (blob is CloudBlockBlob blockBlob)

                {
                    var time = blockBlob.Properties.LastModified;
                    Console.WriteLine("Data", time);

                }
            }

        }
        catch (Exception e)
        {
            //  Block of code to handle errors
            Console.WriteLine("Error", e);

        }

Each IListBlobItem is going to be a CloudBlockBlob, a CloudPageBlob, or a CloudBlobDirectory.

After casting to block or page blob, or their shared base class CloudBlob (preferably by using the as keyword and checking for null), you can access the modified date via blockBlob.Properties.LastModified.

Note that your implementation will do an O(n) scan over all blobs in the container, which can take a while if there are hundreds of thousands of files. There's currently no way of doing a more efficient query of blob storage though, (unless you abuse the file naming and encode the date in such a way that newer dates alphabetically come first). Realistically if you need better query performance I'd recommend keeping a database table handy that represents all the file listings as rows, with things like an indexed DateModified column to search by and a column with the blob path for easy access to the file.

Use the Azure Web Jobs SDK. The SDK has options to monitor for new/updated BLOBs.

Like Yar said, you can use the LastModified property of an individual blob object. Here is a code snippet that shows how to do that, once you have a reference to the correct container:

var latestBlob = container.ListBlobs()
    .OfType<CloudBlockBlob>()
    .OrderByDescending(m => m.Properties.LastModified)
    .ToList()
    .First();

Note: The blob type may not be <CloudBlockBlob>. Be sure to change that if necessary.