Datecolumn：无法将类型为“ System.DateTime”的对象转换为类型为“ System.String”的对象

通过分别获取各列并解析日期列来解决此问题：

var result = from i in dc.vw_Users    where i.id == id    select new    {        i.UserId,        i.id,        i.SiId,        i.FullName,        i.UserName,        i.RoId,        i.Ro,        i.Email,        WelcomeSent = i.WelcomeSent != null && i.WelcomeSent.ToString().Length > 0     ? DateTime.Parse(i.WelcomeSent.ToString())     : new DateTime(),        i.Signed,        i.IsPri,        i.IsApproved,        IsLocked = i.IsLockedOut,        i.LoginStatus,        i.LastLoginDate,        i.SignRights,        i.LastPasswordChangedDate,        i.FailedPasswordAttemptCount,        i.CompleteDate,        i.AccessDate,        i.CertificationDate,        i.CertificateId,        i.progress    };