Question

This is not about encoding URLs its more to do with a problem I noticed where you can have a valid filename on IIS sucha as “test & test.jpg” but this cannot be downloaded due to the & causing an error. There are other characters that do this also that are valid in windows but not for web.

My quick solution is to change the filename before saving using a regex below…

    public static string MakeFileNameWebSafe(string fileNameIn)
    {
        string pattern = @"[^A-Za-z0-9. ]";
        string safeFilename = System.Text.RegularExpressions.Regex.Replace(fileNameIn, pattern, string.Empty);
        if (safeFilename.StartsWith(".")) safeFilename = "noname" + safeFilename;

        return safeFilename;
    }

but I was wondering if there were any better built in ways of doing this.

Answer 1

Built-in I don’t know about.

What you can do is, like you say, scan the original filename and generate a Web-safe version of it.

For such Web-safe versions, you can make it appear like slugs in blogs and blog categories (these are search engine-optimized):

• Only lowercase characters
• Numbers are allowed
• Dashes are allowed
• Spaces are replaced by dashes
• Nothing else is allowed
• Possibly you could replace “&” by “-and-“

So “test & test.jpg” would translate to “test-and-test.jpg”.