csharp 使用LINQ检查列表中的项是否具有其属性之一的特定值，第二种方式使用“out”修饰符来返回va

Posted 2021-05-12

IEnumerable<ReportParameter> reportParameterList = reportParameters as IList<ReportParameter> ?? reportParameters.ToList();
            
DateTime dateFrom;
DateTime dateTo;

string sDateFrom = reportParameterList.Where(i => i.Name == "DATE_FROM" && i.Values.Count == 1).Select(s => s.Values[0]).First();

if (!DateTime.TryParse(sDateFrom, out dateFrom))
{
    dateFrom = TimeService.Instance.now();
}

string sDateTo = reportParameterList.Where(i => i.Name == "DATE_TO" && i.Values.Count == 1).Select(s => s.Values[0]).First();

if (!DateTime.TryParse(sDateTo, out dateTo))
{
    dateTo = TimeService.Instance.now();
}