File Name Validation

In a continuing effort to keep track of my coding notes, here is another function I wrote that I use a lot. It uses "Path" to get a list of invalid characters to check against.

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

namespace DemoSolution
{
    class Program
    {
        static void Main(string[] args)
        {
            string badFileName = @"This!has*INVALID:characters.txt";
            string goodFileName = @"This-has_INVALID.characters.txt";

            Console.WriteLine("badFileName = {0}", badFileName.IsValidFileName());
            // OUTPUT: badFileName = False

            Console.WriteLine("goodFileName = {0}", goodFileName.IsValidFileName());
            // OUTPUT: goodFileName = True
        }
    }

    public static class MyExtensions
    {
        /// 

        /// Checks the string to see if any invalid characters exist for a file name.
        /// 
        /// 
        /// 
        ///     Returns "True" if the file name has no invalid
        ///     characters, else it returns "False".
        /// 
        /// 
        /// string fileName = "Valid_File-Name.txt";
        /// 
        public static bool IsValidFileName(this string FileName)
        {
            // Create the RegEx pattern to match
            Regex BadPathCharacters = new Regex(
                "[" + Regex.Escape(String.Join("", Path.GetInvalidFileNameChars()))
                + "]");

            // See if any of the characters are a match. 
            if (BadPathCharacters.IsMatch(FileName))
            {
                return false;
            }
            return true;
        }
    }
}

When I need to allow only Net Bios characters I use this function. It can be used to make sure a user enters a proper server name.

/// 

/// Will allow text entered into a textbox to be Net Bios safe.
/// If the key pressed is not good, it is fake handled. 
/// 
/// Can be called from XAML like so:
///     
///     
/// NOTE: PreviewTextInput is WPF Device safe as compared to checking the keyboard.
/// 
/// 
/// 
public static void NetBiosAllowedTextOnly(object sender, TextCompositionEventArgs e)
{
    // Get the entered text
    string TheText = e.Text;

    ////////////////////////////////////////////////////////////////////////////
    //    NetBIOS computer names cannot contain the following characters:     //
    //    • backslash (\)           • slash mark (/)                          //
    //    • colon (:)               • asterisk (*)                            //
    //    • question mark (?)       • quotation mark (")                      //
    //    • less than sign (<)      • greater than sign (>)                   //
    //    • vertical bar (|)                                                  //
    ////////////////////////////////////////////////////////////////////////////
    if (-1 < TheText.IndexOfAny(new char[] { '\\', '/', ':', '*', '?', '\"', '<', '>', '|' }))
    {
        // Not allowed character so pretend it was handled.
        e.Handled = true;
    }
    else
    {
        // Allowed character, let it be handled regularly.
        e.Handled = false;
    }
}