1using System;
2using System.Text.RegularExpressions;
3
4namespace Misc
5{
6   public class Helper
7   {
8       public static string RemoveInvalidCharacters(string name)
9       {
10           if(name == null)
11               throw new ArgumentNullException("name");
12
13           //We should trim the input before we do length check.

14           //This way, we could be able to fit in more characters in

15           //our output if there are spaces in the beginning.

16           name = name.Trim();
17
18           string[] invalidCharacters =
19               new string[]
20                   {
21                       "#", "%", "&", "*", ":", "<", ">", "?", "\\", "/", "{", "}", "~", "+", "-", ",", "(", ")", "|",
22                       "."
23                   };
24
25           Regex cleanUpRegex = GetCharacterRemovalRegex(invalidCharacters);
26           string cleanName = cleanUpRegex.Replace(name, string.Empty);
27           cleanName = cleanName.Replace(" ", "%20");
28
29           if (cleanName.StartsWith("_"))
30               cleanName = cleanName.Substring(1);
31
32           if (cleanName.Length > 50)
33               cleanName = cleanName.Substring(0, 50);
34
35           return cleanName;
36       }
37
38       private static Regex GetCharacterRemovalRegex(string[] invalidCharacters)
39       {
40           if(invalidCharacters == null)
41               throw new ArgumentNullException("invalidCharacters");
42
43           if(invalidCharacters.Length == 0)
44               throw new ArgumentException("invalidCharacters can not be empty.", "invalidCharacters");
45
46           string[] escapedCharacters = new string[invalidCharacters.Length];
47
48           int index = 0;
49
50           foreach (string input in invalidCharacters)
51           {
52               escapedCharacters[index] = Regex.Escape(input);
53               index++;
54           }
55
56           return new Regex(string.Join("|", escapedCharacters));
57       }
58}
59
60}
61
62}