我可以在 Expression 主体内传递函数调用以进行 EF 6 查询 C# 7

Question

我有以下代码。我尝试在查询的Where子句的表达式中传递对IsActive的调用，但它不执行

protected Expression<Func<vAccount, bool>> ActiveAccountPredicate => a =>
    (
        IsActive(a)
    )
    && (!a.Foreign || IsShowForeign)
    && (a.RegistrationTypeId != RegistrationType.NotRegistered || IsShowNotRegistered);

public static bool IsActive(vAccount a)
{
    return (a.DepartedDate == null || a.DepartedDate >= DateTime.Now)
            && (a.RegistrationTypeId != RegistrationType.NotRegistered || a.SupoDepartedDate == null || a.SupoDepartedDate >= DateTime.Now)
            && (a.RegistrationTypeId != RegistrationType.NotRegistered || a.RegistrationExpiredDate == null || a.RegistrationExpiredDate >= DateTime.Now);
}

有办法做到这一点吗？

Answer 1

您还需要将

IsActive

写为

Expression

。

public static Expression<Func<vAccount, bool>> IsActive => a =>
{
    return (a.DepartedDate == null || a.DepartedDate >= DateTime.Now)
            && (a.RegistrationTypeId != RegistrationType.NotRegistered || a.SupoDepartedDate == null || a.SupoDepartedDate >= DateTime.Now)
            && (a.RegistrationTypeId != RegistrationType.NotRegistered || a.RegistrationExpiredDate == null || a.RegistrationExpiredDate >= DateTime.Now);
};