Linq查询日期的年份

Question

Here is my code in the controller:

}else if (reports == "Decommissioned")
            {
                if (reports != String.Empty)
                {
                    var date = (Convert.ToInt64(specific)) - 5;
                    desktop = desktop.Where(x => x.dt_date_delivered.Value.Year == date);
                    count = desktop.Where(x => x.dt_date_delivered.Value.Year == date).ToList().Count();
                }
            }

This query in inside a function in the controller. I wonder why is this not working where other controller where I did not put this query in the function, it works. When I try to run this code, the error is Cannot implicity ceonvert type 'System.Collections.Generic.IEnumerable<InSys_Models.Desktop_reports_vw>' to 'System.Collections.Generic.List<InSys.Models.Desktop_reports_vw>'. An explicit conversion exists(are you missing a cast?) Cannot implicity ceonvert type 'System.Collections.Generic.IEnumerable<InSys_Models.Desktop_reports_vw>' to 'System.Collections.Generic.List<InSys.Models.Desktop_reports_vw>'. An explicit conversion exists(are you missing a cast?)

Answer 1

因为desktop.Where（）函数返回IEnumerable，所以您应该调用ToList（）将IEnumerable转换为List：

desktop = desktop.Where(x => x.dt_date_delivered.Value.Year == date).ToList();

Answer 2

您需要在Select的末尾调用ToList才能返回列表，而不是IEnumerable。