protected string GetFile(string fileName)

        {

            string content = null;

            if (File.Exists(fileName))

            {

                content = File.ReadAllText(fileName);

                // or

                using (var fs = File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.Read))

                {

                    using (var sr = new StreamReader(fs))

                    {

                        content = sr.ReadToEnd();

                    }

                }

            }

            return content;

        }