在不使用 AJAX 的情况下重新加载 ASP.NET MVC3 部分视图

Question

I have an MVC3 application with Razor and I created a View that inside renders a Partial View. This is how the main View looks like:

@{Html.RenderPartial("_SearchFilters", Model.SearchFilters);}

@* Other HTML elements *@

Inside the _SearchFilters Partial View I have the following DropDownLists inside a Form element:

Choose Year
          @Html.DropDownListFor(m => m.Year, new SelectList(Model.YearsList, "Value", "Text"), DateTime.Now.Year)

Choose Month
          @Html.DropDownListFor(m => m.Month, new SelectList(Model.MonthsList, "Value", "Text"), Model.Month.ToString(), new { @disabled = "disabled" })


       <input type="submit" value="Display" />

I would like that upon Submit the two DropDownLists keep their status, namely the value selected by the user , when the View is reloaded with the filtered data.

Is there any way to do it without using AJAX?

UPDATE

The ViewModel is as follows:

public class TableSearchFiltersViewModel
{
    public bool YTM { get;  set; }

    public int? Month { get; set; }

    public int? Year { get; set; }

    public IEnumerable<SelectListItem> YearsList
    {
        get
        {
        return Enumerable.Range(2011, (DateTime.Now.Year - 2011 + 4)).Select(m => new SelectListItem
        {
            Value = m.ToString(),
            Text = m.ToString(),
        }).OrderBy(m => m.Value);
        }
    }

    public IEnumerable<SelectListItem> MonthsList
    {
        get
        {
           return Enumerable.Empty<SelectListItem>();
        }
    }

}

Thanks

Francesco

Answer 1

When you submit the form to the corresponding controller action, this action should take as input parameter some view model. This view model's properties will be bound from the input fields contained in the form including the selected value of the two dropdowns. Then the controller action could return the same view which will preserve the selected values of the dropdown boxes.

I would recommend you to use Editor Templates though instead of rendering partials as this will ensure proper naming of the dropdowns and eventually preserve selected values:

@Html.EditorFor(x => x.SearchFilters)

Answer 2

Without ajax not, or you will have to repost the whole form. MVC is a web framework which is not dynamic like a winforms application. You will have to post the changes to your controller and reload the page with the necessary changes, or use ajax to reload these changes.

Answer 3

You could provide the default values for Year and Month properties (to be selected at the first request) and bind those instead of the hardcoded startup values you provided.

So instead of:

@Html.DropDownListFor(m => m.Year, new SelectList(Model.YearsList, "Value", "Text"), DateTime.Now.Year)

Which btw seems erroneous, as selected value (which I suppose DateTime.Now.Year is in your example) should be provided as SelectList 's constructor (instead of DropDownListFor method's) argument. DropDownListFor method doesn't have a 'selected value' argument.

You could write:

@Html.DropDownListFor(m => m.Year, new SelectList(Model.YearsList, "Value", "Text", Model.Year))

and analogously in the second dropdown.

This will make dropdowns keeps the selected values when rendered using the posted model (as Model.Year and Model.Month would hold those). So you should make sure those values won't get overwritten with default ones after subsequent submits.

Answer 4

I don't have IDE at this time so couldn't test but this might work:

Choose Month

EDIT:

 @Html.DropDownListFor(m => m.Month, 
Model.MonthsList.Select(
        t => new SelectListItem {
                 Text = t.Name,
                 Value = t.Value,
                 Selected = t.Value == Model.Month,
        },

 Model.Month.ToString(), new { @disabled = "disabled" })