下拉列表值返回---选择---页面刷新后 [英] Drop down list value returns to ---select--- after page refresh

问题描述

嗨伙计们......不确定我是否在论坛的这一部分，但任何... ...

Hi guys..not sure if im in the part of the forums here but anywho...

Heys guys

Heys guys

因此，在我的应用程序中，用户将从下拉列表中选择一个名称，单击"查看"和相应的值将显示在页面上。

So in my application the user will select a name from the drop down list, click 'view' and the corresponding values will display on page.

然后使用超链接按升序对列表进行排序。  为此，页面会刷新并显示列表的新顺序。

A hyperlink is then used to sort the list in ascending order.  For this to happen the page refreshes and displays the new order of the list.

下拉列表的值返回其原始值'select'，而不是保留所选人员的姓名。

The value of the drop down list returns back to its original value of 'select' instead of remaining the name of the person selected.

我的模特：

My Model:

public class HolidayList
    { 
        public List<Holiday> HList4DD { get; set; }
        public List<Person> PList4DD { get; set; }

        public int currentPersonID { get; set; }
        public IEnumerable<SelectListItem> Categories { get; set; }

        public HolidayList()
        {
            HList4DD = new List<Holiday>();
            PList4DD = new List<Person>();
            }
        }
    }

--------------------------------- -------

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我的控制器：

my controller:

 [HttpPost]
        public ViewResult Index(int HolidayDate)
        {
            var holidays = db.Holidays.Include("Person");

            HolidayList model = new HolidayList();

            model.currentPersonID = HolidayDate;
            model.PList4DD = db.People.ToList();           
            model.Categories = holidays.Select(x => new SelectListItem
                                            {
                                                Value = x.Id.ToString(),
                                                Text = x.Person.Name
                                            }
                                          );


            int data = HolidayDate;

            model.HList4DD = db.Holidays.Where(h => h.PersonId == HolidayDate).ToList();      

            return View(model);

        }

        [HttpGet]
        public ViewResult Index(string sortOrder, int? currentPersonID)
        {
            var holidays = db.Holidays.Include("Person");
 
            HolidayList model = new HolidayList();
 
            //not null
            if (currentPersonID.HasValue)
            {
                model.currentPersonID = currentPersonID.Value;

            }
            else
            {
                model.currentPersonID = 0;
            }

            model.PList4DD = db.People.ToList();

            ViewBag.NameSortParm = String.IsNullOrEmpty(sortOrder) ? "date" : "";
            var dates = from d in db.Holidays
                        where d.PersonId == currentPersonID.Value
                        select d;
     
            switch (sortOrder)
            {
                case "date":
                    dates = dates.OrderBy(p => p.HolidayDate);
                    break;
            }

            model.HList4DD = dates.ToList();

            return View(model);
        }

-----------------------

-----------------------

my view

my view

我在这里尝试了许多不同的尝试，以下代码有效，但有下拉列表问题

i've tried a number of different attempts here, the following code worked but has the drop list problem

@Html.DropDownListFor(model => model.HList4DD.First().HolidayDate,
                                new SelectList(Model.PList4DD, "Id", "Name"),
                               // Model.currentPersonID
                                "---Select---"
                                )  *@

-----------

-----------

我的解决方法是：

my attempts to resolve this are:

   @* @Html.DropDownList("HolidayDate", Model.Categories, "---Select---")*@

           @*  @Html.DropDownListFor("HolidayDate", x => x.HolidayDate, Model.Categories)
                              *@

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任何帮助非常感谢

Any help much appreciated

thaks

thaks

推荐答案

ASP.NET MVC论坛
http://forums.asp.net/1146.aspx 是这类问题的最好地方

The ASP.NET MVC forums http://forums.asp.net/1146.aspx is the better place for such questions

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