ASP.Net MVC 3中的下拉选择

Question

I am new to asp.net MVC 3. I want to create dropdown for each year, month and day. I created a helper class that collects common function. See below.

Common

Public Shared Function GetYearsList() As List(Of SelectListItem)

    Dim items As New List(Of SelectListItem)

    For i = -1 To 2500
        Dim item As New SelectListItem

        item.Text = Now.AddYears(i).Year.ToString()
        item.Value = Now.AddYears(i).Year.ToString()

        If i = Now.Year Then
            item.Selected = True
        End If

        items.Add(item)
    Next

    Return items

End Function

In the Controller class.

Function Index() As ActionResult

    ViewData("Year") = Command.GetYearsList()
    ViewData("Month") = Command.GetMonthsList()
    ViewData("Day") = Command.GetDaysList()

    Return View()

End Function

In the View page.

@Html.DropDownList("Year", DirectCast(ViewData("Year"), List(Of SelectListItem)), New With {.onchange = "setDate();"})

But it didnot select current year. How can I do to select current year. Otherwise has other solution for that? Thanks all.

Answer 1

I show what you want but in C#. I think you can easily rewrite it to VB.

Firs of all, make a view model class for the view.

public class SomeViewModel
{
    public SomeViewModel()
    {
        this.Years = new List<int>();

        for (int i = -1; i <= 2500; i++)
        {
            this.Years.Add(DateTime.Now.AddYears(i).Year);
        }

        this.SelectedYear = DateTime.Now.Year;
    }

    public int SelectedYear { set; get; }
    public List<int> Years { set; get; }
}

It has a property that contains the years, and another for the selected one.

Second, make a simple controller method:

public ActionResult Index()
{
    var model = new SomeViewModel();

    return View(model);
}

After this, make your strongly typed view:

@model YourAppNameSpace.ViewModels.SomeViewModel

...

@Html.DropDownListFor(model => model.SelectedYear, new SelectList(Model.Years))

It will make a DropDownList containing the years, and the selected year is the current year.