Comments on: Check Valid File Path in C#

By: Imi

Imi — Fri, 02 Jul 2010 12:07:30 +0000

Remember, that there are special files under windows which cannot be created (or have undesired effects when attempting to) and whose characters are not in Path.InvalidFileNameChars

For example files named "COM1″, "PRN" or just "NUL".

Look here: http://social.technet.microsoft.com/Forums/en/w7itprogeneral/thread/e22c021d-d188-4ff2-a4dd-b5d58d979c58

By: srikanth.gaddala

srikanth.gaddala — Fri, 24 Jul 2009 12:17:20 +0000

hi Robin,
the code you have provided for RemoveInvalidFileNameChars()
is really very useful to me.
thanks a lot…

Srikanth.g

By: Romy

Romy — Wed, 25 Mar 2009 16:33:17 +0000

Try:
private static void CheckValidPath(string pathFile)
{
string fullPath = pathFile;
FileIOPermission permission = new FileIOPermission(PermissionState.None);
permission.AllFiles = FileIOPermissionAccess.PathDiscovery;
permission.Assert();
try { fullPath = Path.GetFullPath(pathFile); }
finally { CodeAccessPermission.RevertAssert(); }

FileIOPermission checkFile = new FileIOPermission(FileIOPermissionAccess.AllAccess, fullPath);
checkFile.Demand();
}

Regards,
Romy

By: Robin

Robin — Sun, 25 Jan 2009 13:12:49 +0000

To get a valid FILE NAME after removing the Invalid file name characters, you can use the following function.

public static string RemoveInvalidFileNameChars(string fileName)
{
char[] invalidFileChars = Path.GetInvalidFileNameChars();

foreach (char invalidFChar in invalidFileChars)
{
fileName = fileName.Replace(invalidFChar.ToString(),"");
}
return fileName;

}

By: tk

tk — Wed, 17 Sep 2008 12:39:49 +0000

>will validate an absolute file path on a Windows PC in most cases

An obvious execption is filenames in non-English
(ie other characters than a-z)

Still, thanks