CODEWITHSUNDEEP
c#.netwpf
anon
anon

Reputation:

How to check if a String is a valid name for a FrameworkElement in WPF?

In my code I'm assigning a String to the name property of a FrameworkElement. This String is automatically generated from another part of the application and represents methods name in Java source code and therefore I want to check if it contains a valid name.

Currently I'm doing it that way:

        private string getValidName(String s)
        {
            return s.Replace("<", "").Replace(">", "").Replace("#", "").Replace("(", "").Replace(")", "").Replace(",", "").Replace(".", "").Replace("$", "").Replace(" ", "");
        }

But the problem is that I don't know which letters I have to replace. For example in this code [ and ] are missing as I found out when I was hit with an Exception.

So my question is. Is there a list of allowed symbols? And if yes how can I implement this in a reasonable way?

Upvotes: 3

Views: 2465

Answers (2)

Danko Durbić
Danko Durbić

Reputation: 7237

To avoid potential duplicates, I would also consider replacing each occurence of an invalid character with something unique, for example, its hexadecimal representation in the UTF-8 encoding:

Regex.Replace( s, @"[^a-zA-Z0-9]",
               m => {
                      var bytes = Encoding.UTF8.GetBytes( m.Value );
                      var hexs = bytes.Select( b => string.Format( "_{0:x2}", b ) );
                      return String.Concat( hexs );
                     } );

Upvotes: 4

Daniel Hilgarth
Daniel Hilgarth

Reputation: 174299

IMHO, the most pragmatic way would be to replace everything that is not [a-z][A-Z][0-9] with an underscore and additionally put an underscore in front. With this, you can change any arbitrary string into a valid identifier.
I know that this doesn't exactly answer your question, but I think it is still worth thinking about it.

You can achieve this with the following code:

var result = "_" + Regex.Replace(input, @"[^a-zA-Z0-9]", "_");

Upvotes: 7

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