Question

如何使用控制器搜索日期范围？到目前为止，我无法使用下面使用的代码解决它。搜索旅行名称＆amp;国家正在努力。（P.s我是这种编程语言的新手......）提前谢谢你。

控制器

public ActionResult Index(string search, DateTime? startdate, DateTime?  enddate)
    {
        if (Session["StaffName"] != null)
        {
            //original
            DateTime str = DateTime.UtcNow;
            ViewBag.Datetime = str;
            ViewBag.startdate = startdate;
            ViewBag.enddate = enddate;
            var Trips = from x in db.Trips
                        select x;
            if (search != null)
            {
                return View(Trips.Where(x => x.TripName.Contains(search) || x.Country.Contains(search)  || search == null).ToList());
            }
            if (startdate != null && enddate != null)
            {
                return View(Trips.Where(x =>  startdate > x.startDate && x.endDate < enddate ).ToList());
            }
            return View(Trips.ToList());
        }
    }

Answer 1

您可以使用此修改后的代码...

public ActionResult Index(string search, DateTime? startdate, DateTime? enddate)
{
    if (Session["StaffName"] != null)
    {
        //original
        DateTime str = DateTime.UtcNow;
        ViewBag.Datetime = str;
        ViewBag.startdate = startdate;
        ViewBag.enddate = enddate;
        var Trips = from x in db.Trips
                select x;
        if (search != null)
        {
            if (startdate != null && enddate != null)
            {
                return View(Trips.Where(x =>  x.TripName.Contains(search) || x.Country.Contains(search)  || search == null && (startdate > x.startDate && x.endDate < enddate)).ToList());
            }
            else
            {
                return View(Trips.Where(x => x.TripName.Contains(search) || x.Country.Contains(search)  || search == null).ToList());
            }
        }
        if (startdate != null && enddate != null)
        {
            return View(Trips.Where(x => startdate > x.startDate && x.endDate < enddate)).ToList());
        }
        return View(Trips.ToList());
    }
}

Answer 2

如果结果评估为if，则控制器代码中的true块将返回视图，因此如果search不是null，则立即退出方法并且永远不会根据startdate和/或enddate值过滤结果。

您需要创建IQueryable<Trips>并在每个if块中使用.Where()子句修改查询，然后在结束时根据过滤后的结果返回视图。

请注意，我假设用户可以在没有startdate的情况下输入enddate，反之亦然

public ActionResult Index(string search, DateTime? startdate, DateTime? enddate)
{
    ViewBag.Datetime = DateTime.UtcNow;
    ViewBag.startdate = startdate;
    ViewBag.enddate = enddate;

    IQueryable<Trips> trips = db.Trips;

    if (search != null)
    {
        trips = trips.Where(x => x.TripName.Contains(search) || x.Country.Contains(search);
    }
    if (startdate.HasValue)
    {
        trips = trips.Where(x => x.startDate > startdate.Value);
    }
    if (enddate.HasValue)
    {
        trips = trips.Where(x => x.enddate < enddate.Value);
    }
    // At this point the query has generated a SQL statement based on the conditions above,
    // but it will not be executed until the until the next line - i.e. when calling .ToList()
    return View(trips.ToList());
}

注意，不清楚您是否真的想要x => x.startDate > startdate.Value或x => x.startDate >= startdate.Value，并且根据您的存储日期是否也包含时间组件，您可能希望使用x => x.startDate > startdate.Value.Date（同上对于enddate）

作为旁注，您应该使用视图模型而不是ViewBag来将值传递给视图。此外，您使用if (Session["StaffName"] != null)表示您的设计存在问题。

如何搜索日期范围ASP.NET MVC？

控制器

2 个答案: