How can I truncate my strings with a “…” if they are too long?

Question

Hope somebody has a good idea. I have strings like this:

abcdefg
abcde
abc

What I need is for them to be trucated to show like this if more

Answer 1

Maybe it is better to implement a method for that purpose:

string shorten(sting yourStr)
{
//Suppose you have a string yourStr, toView and a constant value 

    string toView;
    const int maxView = 3;

    if (yourStr.Length > maxView)
        toView = yourStr.Substring(0, maxView) + " ..."; // all you have is to use Substring(int, int) .net method
    else
        toView = yourStr;
return toView;
}

Answer 2

Here is the logic wrapped up in an extension method:

public static string Truncate(this string value, int maxChars)
{
    return value.Length <= maxChars ? value : value.Substring(0, maxChars) + "...";
}

Usage:

var s = "abcdefg";

Console.WriteLine(s.Truncate(3));

Answer 3

All very good answers, but to clean it up just a little, if your strings are sentences, don't break your string in the middle of a word.

private string TruncateForDisplay(this string value, int length)
{
  if (string.IsNullOrEmpty(value)) return string.Empty;
  var returnValue = value;
  if (value.Length > length)
  {
    var tmp = value.Substring(0, length) ;
    if (tmp.LastIndexOf(' ') > 0)
       returnValue = tmp.Substring(0, tmp.LastIndexOf(' ') ) + " ...";
  }                
  return returnValue;
}

Answer 4

Code behind:

string shorten(sting s)
{
    //string s = abcdefg;
    int tooLongInt = 3;

    if (s.Length > tooLongInt)
        return s.Substring(0, tooLongInt) + "..";

    return s;
}

Markup:

<td><%= shorten(YOUR_STRING_HERE) %></td>

Answer 5

Here's a version that accounts for the length of the ellipses:

    public static string Truncate(this string value, int maxChars)
    {
        const string ellipses = "...";
        return value.Length <= maxChars ? value : value.Substring(0, maxChars - ellipses.Length) + ellipses;
    }

Answer 6

I has this problem recently. I was storing a "status" message in a nvarcharMAX DB field which is 4000 characters. However my status messages were building up and hitting the exception.

But it wasn't a simple case of truncation as an arbitrary truncation would orphan part of a status message, so I really needed to "truncate" at a consistent part of the string.

I solved the problem by converting the string to a string array, removing the first element and then restoring to a string. Here is the code ("CurrentStatus" is the string holding the data)...

        if (CurrentStatus.Length >= 3750)
        {
            // perform some truncation to free up some space.

            // Lets get the status messages into an array for processing...
            // We use the period as the delimiter, then skip the first item and re-insert into an array.

            string[] statusArray = CurrentStatus.Split(new string[] { "." }, StringSplitOptions.None)
                                    .Skip(1).ToArray();

            // Next we return the data to a string and replace any escaped returns with proper one.
            CurrentStatus = (string.Join(".", statusArray))
                                    .Replace("\\r\\n", Environment.NewLine);


        }

Hope it helps someone out.