C# 列表视图控制器方法中的if语句_C#_Asp.net Mvc

C# 列表视图控制器方法中的if语句

c# asp.net-mvc

C# 列表视图控制器方法中的if语句,c#,asp.net-mvc,C#,Asp.net Mvc,我的控制器方法中包含以下代码，用于向成员类型列表视图提供数据： [HttpGet] public ActionResult SelectMembershipType(int clubId) { //Populate the list var membershipTypes = from s in db.MembershipTypes where (s.ClubId == clubId &

我的控制器方法中包含以下代码，用于向成员类型列表视图提供数据：

[HttpGet]
public ActionResult SelectMembershipType(int clubId)
    {
        //Populate the list
        var membershipTypes = from s in db.MembershipTypes
                              where (s.ClubId == clubId  && s.Dormant == false)
                              orderby s.Type
                              select s;

        //Generate the ViewModel with the appropriate membership types
        var viewModel = membershipTypes.Select(t => new   SelectMembershipTypeViewModel
        {
            //Select appropriate Cost based on current month
            if(DateTime.Now.Month == t.ReducedMonth)
            {
                Cost = t.ReducedCost;
            }
            else
            {
                Cost = t.Cost;
            }
            ClubId = club.ClubId,
            Name = club.Name,              
            MembershipName = t.Type,
            MembershipType = t.MembershipTypeClassification.Type,
            MembershipTypeId = t.MembershipTypeId,
        });
        return View(viewModel);
    }

我输入的if语句不起作用，它抛出了几个错误。我试图将if语句应用于Cost值，即如果每个成员类型的todays month等于数据库中的reduced month，则使Cost值等于成员类型reduced Cost值，如果不是，则改为使其等于其成本。每种会员资格类型都可以有不同的缩减月数和成本

我不确定正确的语法来正确地编写代码

我输入的if语句不起作用，它抛出了几个错误

是的，它会-你已经把它放在一个对象初始值设定项中了。对象初始值设定项不是任意的代码块-基本上，它们是

property=value

赋值的列表。（比这稍微多一些，但是…）

幸运的是，在这种情况下，您可以使用条件运算符：

var viewModel = membershipTypes.Select(t => new SelectMembershipTypeViewModel
{
    //Select appropriate Cost based on current month
    Cost = DateTime.Now.Month == t.ReducedMonth ? t.ReducedCost : t.Cost,
    ClubId = club.ClubId,
    Name = club.Name,              
    MembershipName = t.Type,
    MembershipType = t.MembershipTypeClassification.Type,
    MembershipTypeId = t.MembershipTypeId,
});

这将编译，但由于将查询转换为SQL，因此可能无法工作。您可能需要先提取

DateTime.Now.Month

部分：

int month = Date.Now.Month;
var viewModel = membershipTypes.Select(t => new SelectMembershipTypeViewModel
{
    //Select appropriate Cost based on current month
    Cost = t.ReducedMonth == month ? t.ReducedCost : t.Cost,
    ClubId = club.ClubId,
    Name = club.Name,              
    MembershipName = t.Type,
    MembershipType = t.MembershipTypeClassification.Type,
    MembershipTypeId = t.MembershipTypeId,
});

请注意，

DateTime.Now.Month

将是此处服务器时区中的月份。。。这就是你想要的吗？假设你想让它在一个特定的时区，我会明确地说。。。否则，您可能会遇到一些难以诊断的问题