Use LastIndexOf(Char) to find the last directory separator character in a string and to extract the file name : String Search « String « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. String
3. String Search

using System;
using System.IO;

public class MainClass
{
   public static void Main()
   {
      string filename;

      filename = ExtractFilename(@"C:\temp\notafile.txt");
      Console.WriteLine("{0}", String.IsNullOrEmpty(filename) ? "<none>" : filename);
   }

   public static string ExtractFilename(string filepath)
   {
      if (filepath.Trim().EndsWith(@"\"))
         return String.Empty;

      int position = filepath.LastIndexOf('\\');
      if (position == -1)
      {
         if (File.Exists(Environment.CurrentDirectory + Path.DirectorySeparatorChar + filepath)) 
            return filepath;
         else
            return String.Empty;
      }
      else
      {
         if (File.Exists(filepath))
            return filepath.Substring(position + 1);
         else
            return String.Empty;
      }
   }
}