/// <summary>
/// Generates a new instance of HashInfo which stores information about the hash
/// </summary>
/// <param name="filename">The name of the file that has been hashed</param>
/// <param name="hash">The file's hash</param>
/// <returns>Returns a new instance of HashInfo containing information avout the specified file. On error returns null</returns>
private HashInfo getHashInfo(string filename, string hash)
{
//check if file exists and hash is valid
if (!File.Exists(filename) || hash.IsNullOrEmpty())
return null;
//Initialize new instance of HashInfo
var result = new HashInfo() { FileName = filename, Hash = hash };
//Load information about the file from disk and set HashInfo properties
var info = new FileInfo(filename);
result.Created = info.CreationTimeUtc;
result.LastEdited = info.LastWriteTimeUtc;
result.Size = info.Length;
return result;
}