/// <summary>
/// locate one text string within a second text string,
/// and return the number of the starting position of the first
/// text string from the first character of the second text string.
/// </summary>
/// <param name="args"><para>
/// The args contains 2 - 3 items: find_text, within_text, [start_num].
/// </para>
/// <para>
/// Find_text is the text you want to find.
/// </para>
/// <para>
/// Within_text is the text in which you want to search for find_text.
/// </para>
/// <para>
/// [Start_num] is the character number in within_text at which you want to
/// start searching, the default value is 1.
/// </para></param>
/// <returns>
/// A <see cref="T:System.String" /> value that indicates the evaluate result.
/// </returns>
public override object Evaluate(object[] args)
{
base.CheckArgumentsLength(args);
string s = CalcConvert.ToString(args[0]);
string str2 = CalcConvert.ToString(args[1]);
int startIndex = CalcHelper.ArgumentExists(args, 2) ? CalcConvert.ToInt(args[2]) : 1;
startIndex--;
if (startIndex < 0)
{
return(CalcErrors.Value);
}
int index = -1;
try
{
if ((s.IndexOf('*') == -1) && (s.IndexOf('?') == -1))
{
index = str2.ToLower().IndexOf(s.ToLower(), startIndex);
}
else
{
Match match = new Regex(LookupHelper.CreateStringcomparisonRegexPattern(s).ToLower()).Match(str2.ToLower(), startIndex);
if ((match != null) && match.Success)
{
index = match.Index;
}
}
}
catch
{
}
if (index == -1)
{
return(CalcErrors.Value);
}
return((int)(index + 1));
}
