/// <summary>
/// 初始化一个<see cref="FilterGroup"/>类型的新实例
/// </summary>
/// <param name="operateCode">条件间操作方式的前台码</param>
public FilterGroup(string operateCode)
: this(FilterHelper.GetFilterOperate(operateCode))
{
}
/// <summary>
/// 初始化一个<see cref="FilterRule"/>类型的新实例
/// </summary>
/// <param name="field">数据名称</param>
/// <param name="value">数据值</param>
/// <param name="operateCode">操作方式的前台码</param>
public FilterRule(string field, object value, string operateCode)
: this(field, value, FilterHelper.GetFilterOperate(operateCode))
{
}