GetInvalidFileNameChars Method

Path.GetInvalidFileNameChars Method ()

 

Gets an array containing the characters that are not allowed in file names.

Namespace:   System.IO
Assembly:  mscorlib (in mscorlib.dll)

public static char[] GetInvalidFileNameChars()

Return Value

Type: System.Char[]

An array containing the characters that are not allowed in file names.

The array returned from this method is not guaranteed to contain the complete set of characters that are invalid in file and directory names. The full set of invalid characters can vary by file system. For example, on Windows-based desktop platforms, invalid path characters might include ASCII/Unicode characters 1 through 31, as well as quote ("), less than (<), greater than (>), pipe (|), backspace (\b), null (\0) and tab (\t).

The following code example demonstrates the GetInvalidFileNameChars method and the GetInvalidPathChars method to retrieve invalid characters.

using System;
using System.IO;

namespace PathExample
{
    class GetCharExample
    {
        public static void Main()
        {
            // Get a list of invalid path characters.
            char[] invalidPathChars = Path.GetInvalidPathChars();

            Console.WriteLine("The following characters are invalid in a path:");
            ShowChars(invalidPathChars);
            Console.WriteLine();

            // Get a list of invalid file characters.
            char[] invalidFileChars = Path.GetInvalidFileNameChars();

            Console.WriteLine("The following characters are invalid in a filename:");
            ShowChars(invalidFileChars);
        }

        public static void ShowChars(char[] charArray)
        {
            Console.WriteLine("Char\tHex Value");
            // Display each invalid character to the console.
            foreach (char someChar in charArray)
            {
                if (Char.IsWhiteSpace(someChar))
                {
                    Console.WriteLine(",\t{0:X4}", (int)someChar);
                }
                else
                {
                    Console.WriteLine("{0:c},\t{1:X4}", someChar, (int)someChar);
                }
            }
        }
    }
}
// Note: Some characters may not be displayable on the console.
// The output will look something like:
//
// The following characters are invalid in a path:
// Char    Hex Value
// ",      0022
// <,      003C
// >,      003E
// |,      007C
// ...
//
// The following characters are invalid in a filename:
// Char    Hex Value
// ",      0022
// <,      003C
// >,      003E
// |,      007C
// ...

Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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