Validating a filename in c# [duplicate]

Question

Possible Duplicate:
How check if given string is legal (allowed) file name under Windows?

I am new to stackoverflow. I know its a silly question, but I am stuck in it. I want to validate a filename so that it should only accept legal path. I have tried the below code:

if (txtFileName.IndexOfAny(System.IO.Path.GetInvalidFileNameChars()) != -1) 
{   
   MessageBox.Show("The filename is invalid");   
   return; 
} 

It worked, however, I was a bit confused whether it will fully work or not so I wanted to know other answers too. I think we can also validate a filename using Regular Expression too. Any help will be great.

Answer 1

This will work as expected.

There's no need to invent a regular expression to do this as if the set of invalid characters ever changes you're code will be out of date, whereas this call will still work as expected.

Answer 2

That's the correct way to go. In future, if your program will be ported to a different operating system, it will continue to work. Hand made solutions will be less effective.

Answer 3

Try this:

bool bOk = false; 
try 
{ 
    new System.IO.FileInfo(fileName); 
    bOk = true; 
} 
catch (ArgumentException) 
{ 
} 
catch (System.IO.PathTooLongException) 
{ 
} 
catch (NotSupportedException) 
{ 
} 

if (!bOk) 
{ 
    // ... 
} 
else 
{ 
    // ... 
}