iterate through azure storage absolute path c#

Question

 CloudStorageAccount cloudStorageAccount = CloudStorageAccount.Parse(ConfigurationManager.AppSettings["storageConnectionString"]);
            CloudFileClient fileClient = cloudStorageAccount.CreateCloudFileClient();
            CloudFileShare fileShare = fileClient.GetShareReference(ConfigurationManager.AppSettings["shareName"]);
            var sourceName = fileShare.GetRootDirectoryReference().GetDirectoryReference((ConfigurationManager.AppSettings["sourceName"]));

I want to check which is latest file uploaded into sourcename I tried using below code -

sourceName.Uri = {https://test.file.core.windows.net/XC/MainFolder/}
sourceName.Uri.AbsolutePath = {/XC/MainFolder/}

 var directory = new DirectoryInfo(sourceName.Uri.AbsolutePath);
            var myFile = (from f in directory.GetFiles()
                          orderby f.LastWriteTime descending
                          select f).First();

error as - System.IO.DirectoryNotFoundException: 'Could not find a part of the path 'C:\XC\MainFolder'.'

which is obvious as it is not a local folder.

how can i use https://test.file.core.windows.net/XC/MainFolder/ to loop and check the latest file ? instead go into each and every file and sub-folder and check its lastModified property , is there any wasy way to do?