/// <summary>
/// Gets a filter with a criteria in string representation.
/// </summary>
/// <param name="columnName">
/// The name of the column for which the criteria should be generated.
/// </param>
/// <returns>a string representing the current filter criteria</returns>
public override string GetFilter(string columnName)
{
if (!HasFilter)
{
return("");
}
return(string.Format(FILTER_FORMAT, columnName, _enumerationSource.GetFilterFromValue(_combo.SelectedItem)));
}
