c# - 无法将字符串转换为 DateTime

Question

我在将字符串转换为 DateTime 时遇到问题，这是错误

我使用了此链接中显示的解决方案 enter link description here并使用 DateTime.Parse，但我一直收到此错误

这是我的类(class)表:

 public partial class Schedule : BaseEntity
    {

        public string Day { get; set; }
        public string Note { get; set; }
        public DateTime Begin { get; set; }
        public DateTime End { get; set; }

     }

请帮忙，谢谢更新:这是查询

var Schedules = new List<Schedule>
{
    new Schedule
    { 
        Day="Lundi", Note="note", Begin=Convert.ToDateTime("2013-04-24 17:47:03"), 
        End=Convert.ToDateTime("2013-05-24 17:47:03"),
        ClassId = context.Classes.Where(c=>c.Libel=="Class 1").FirstOrDefault().Id, 
        SubjectLevelId = context.SubjectLevels.Where(cbv=>cbv.Coef==1).FirstOrDefault().Id, 
        ClassRoomId = context.ClassRooms.Where(c=>c.Libel=="ClassRoom1").FirstOrDefault().Id, 
        TeacherId = context.Teachers.Where(c=>c.FirstName=="mouna").FirstOrDefault().Id, 
        SchoolYearId=  context.SchoolYears.Where(f=>f.Begin==DateTime.Parse("15/09/2015")).FirstOrDefault().Id
    },
};
Schedules.ForEach(s =>
{
    s.ObjectState = Repository.Pattern.Infrastructure.ObjectState.Added;
    context.Schedules.Add(s);
    context.SaveChanges();
});

Answer 1

将您的代码更改为如下内容:

var beginDateTime = Convert.ToDateTime("2013-04-24 17:47:03");
var endDateTime = Convert.ToDateTime("2013-05-24 17:47:03");
var schoolYearBeginDate = DateTime.Parse("15/09/2015");
var Schedules = new List<Schedule>
{
    new Schedule
    { 
        Day="Lundi", 
        Note="note", 
        Begin = beginDateTime, 
        End=endDateTime,
        ClassId = context.Classes.Where(c=>c.Libel=="Class 1").FirstOrDefault().Id, 
        SubjectLevelId = context.SubjectLevels.Where(cbv=>cbv.Coef==1).FirstOrDefault().Id, 
        ClassRoomId = context.ClassRooms.Where(c=>c.Libel=="ClassRoom1").FirstOrDefault().Id, 
        TeacherId = context.Teachers.Where(c=>c.FirstName=="mouna").FirstOrDefault().Id, 
        SchoolYearId=  context.SchoolYears.Where(f=>f.Begin==schoolYearBeginDate).FirstOrDefault().Id
    },
};

此外，这些最终会抛出空引用异常:

context.Classes.Where(c=>c.Libel=="Class 1").FirstOrDefault().Id

将它们更改为:

context.Classes.Where(c=>c.Libel=="Class 1").Select(c => c.Id).FirstOrDefault()

如果 ClassId 等不可为空，那么您应该这样做:

context.Classes.Where(c=>c.Libel=="Class 1").First().Id