/// <summary>
/// 判断value是否存在于列表中
/// </summary>
/// <param name="lst">数据源</param>
/// <param name="value">要判断的值</param>
/// <returns></returns>
public static bool Contains(this IEnumerator <int> lst, int?value)
{
return(lst.Contains(value.GetValueOrDefault()));
}
