File Helper for working with files...will add more methods in the future.

FileHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

public static class FileHelper
{

    /// <summary>
    /// Read the contents of a file and return as a string.
    /// This method closes the file as soon as it has been read.
    /// </summary>
    /// <param name="fileName"></param>
    /// <returns></returns>
    public static string GetFileContents(string fileName)
    {
        StringBuilder results = new StringBuilder();

        using (FileStream fs = File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
        using (BufferedStream bs = new BufferedStream(fs))
        using (StreamReader sr = new StreamReader(bs))
        {
            string line;
            while ((line = sr.ReadLine()) != null)
            {
                results.AppendLine(line);
            }
        }

        var what = results.ToString();

        return what;
    }
    
    /// <summary>
    /// Writes string to file
    /// </summary>
    /// <param name="fileName">full file path and name</param>
    /// <param name="content">string to be written to the file</param>
    /// <param name="append">if true the file will be appended to. if false the file will be overwritten. default is false</param>
    public static void WriteStringToFile(String fileName, String content, bool append = false) 
    {
        using (StreamWriter outfile = new StreamWriter(fileName, append))
        {
            outfile.Write(content);
        }

    }
}