Truncate string on whole words in .Net C#

Question

Hi,

I am trying to truncate some long text in C#, but I don't want my string to be cut off part way through a word. Does anyone have a function that I can use to truncate my string at the end of a word?

E.g:

"This was a long string..."

Not:

"This was a long st..."

Thanks, Tim

Answer 1

Try the following... it is pretty rudimentary. Just finds the first space starting at the desired length.

public static string TruncateAtWord(this string value, int length) {
    if (value == null || value.Length < length || value.IndexOf(" ", length) == -1)
        return value;

    return value.SubStr(0, value.IndexOf(" ", length));
}

Answer 2

If you are using windows forms, in the Graphics.DrawString method, there is an option in StringFormat to specify if the string should be truncated, if it does not fit into the area specified. This will handle adding the ellipsis as necessary.

http://msdn.microsoft.com/en-us/library/system.drawing.stringtrimming.aspx

Answer 3

Thanks for your answer Dave. I've tweaked the function a bit and this is what I'm using ... unless there are any more comments ;)

public static string TruncateAtWord(this string input, int length)
{
    if (input == null || input.Length < length)
        return input;
    int iNextSpace = input.LastIndexOf(" ", length);
    return string.Format("{0}...", input.Substring(0, (iNextSpace > 0) ? iNextSpace : length).Trim());
}

Answer 4

Anyone checked this?

http://www.codeproject.com/Articles/47930/String-Truncation-Function-for-Csharp.aspx