Problem with Substring() - ArgumentOutOfRangeException

Question

I have a repeater that displays data from my Projects table. There are projectId, name and description. I use Substring(1, 240) on description. But sometimes the string is s

Answer 1

string dec = "description";
string result = dec.Substring( 0, dec.Length > 240 ? 240 : dec.Length )

Answer 2

An extension method:

public static string SafeSubstring(this string text, int start, int length)
{
   if (start >= text.Length)
      return "";            
   if (start + length > text.Length)
      length = text.Length - start;         
   return text.Substring(start, length);
}

Answer 3

Let's try to keep this simple...

We only need to truncate to a given max length, so how about we call it what it is:

description.TruncateTo(240);

The extension method that enables the above (ellipsis is appended by default if truncated):

public static class StringExtensions
{
    public static string TruncateTo(this string val, int maxLength, bool ellipsis = true)
    {
        if (val == null || val.Length <= maxLength)
        {
            return val;
        }

        ellipsis = ellipsis && maxLength >= 3;
        return ellipsis ? val.Substring(0, maxLength - 3) + "..." : val.Substring(0, maxLength);
    }
}

Answer 4

Based on Jon Skeet's answer, I think it should be checking for null or else it's not exactly a safe method :)

public static string SafeSubstring(this string text, int start, int length)
{
    if (text == null) return null;      

    return text.Length <= start ? ""
        : text.Length - start <= length ? text.Substring(start)
        : text.Substring(start, length);
}

Answer 5

Text='<%# Eval("Description").ToString().Substring(1, Math.Min(240, Eval("Description").ToString().Length - 1)) + "..." %>'