Code Behind:

public string GetTrimmedText(strText) <--- Identifier Expected Here
    {

        string strReturn = strText;

        if(! String.IsNullOrEmpty(strText))
        {
          if(strText.Trim.Length() > 5)
          {
           strReturn= strText.substring(0,5) + "....";
          }
        }

        return strReturn;

    }


Control:

Text='<%# GetTrimmedText(Eval("Title")) %>'