.Net - code snippet to find and replace in any physical file

This is the code snippet to find and replace the content of the physical file.

using System;
using System.IO;
using System.Text.RegularExpressions;

/// <summary>
/// Replaces text in a file.
/// </summary>
/// <param name="filePath">Path of the text file.</param>
/// <param name="searchText">Text to search for.</param>
/// <param name="replaceText">Text to replace the search text.</param>
static public void ReplaceInFile( string filePath, string searchText, string replaceText )
{
   StreamReader reader = new StreamReader( filePath );
   string content = reader.ReadToEnd();
   reader.Close();

   content = Regex.Replace( content, searchText, replaceText );

   StreamWriter writer = new StreamWriter( filePath );
   writer.Write( content );
   writer.Close();
}