Every so once in a while the issue rises where you need to truncate a piece of text to a certain maximum length.
Now that in itself is not so hard to do. But the result can look quite strange when the truncation point happens in the middle of a word.
As always
StackOverflow provides a good starting point.
I just thought using a
Regular Expression would be more concise. So here is my solution:
private const string Ellipsis
= "...";// Match word boundaries at the end of a word.private static Regex wordRegex
= new Regex
(@"(?<=\w)(?!\w)", RegexOptions.
Compiled); private static string Truncate
(string source,
int length
){ int maxLength
= length
- Ellipsis.
Length; if (source
!= null && source.
Length > length
) { int afterLastWordIndex
= 0; foreach (Match m
in wordRegex.
Matches(source
)) { if (m.
Index <= maxLength
) { afterLastWordIndex
= m.
Index; } else { break
; } } return String.
Concat(source.
Substring(0, afterLastWordIndex
), Ellipsis
); } return source
;}static void Main
(string[] args
){ string source
= "The quick brown fox jumps over the lazy dog"; Console.
WriteLine(" 1 2 3 4 5"); Console.
WriteLine("12345678901234567890123456789012345678901234567890"); Console.
WriteLine(source
); int[] truncingLengths
= { 0,
1,
3,
4,
8,
9,
10,
15,
19,
20,
21,
22,
23,
28,
30,
33,
42,
43,
50 }; foreach (int truncAt
in truncingLengths
) { Console.
WriteLine("{0}: \"{1}\"", truncAt, Truncate
(source, truncAt
)); } Console.
ReadLine();}
