ASP.NET passing List back to controller from IEnumerable @model inside Table header ActionLink with non-indexing

问题

I have been reviewing possible ways to return a View's @model information which is of type IEnumerable back to the controller, so that if I sort/filter on a query from database, I can refine the return each iteration without restarting with a fresh full list being returned. All the ways show you need to POST back based on model[index] which works if you are inside a for loop. But I am working with sending the collection back from an @HTML.ActionLink within a table's header section, so there is no possible indexing available.

My WebAPI setup is based on this where they show how to sort and filter. I am trying to make it a little more complex in that after I filter a list based on my original DB query, I will then be able to sort (from a clickable-actionLink on a table's header column) from that filtered list; where as currently it would just sort from a fresh complete list.

The only way I can think of to do this is pass back (by a POST) to the controller the updated list of the customClass.

@Html.ActionLink("Name", "Index", new { orderBy = ViewBag.sortByName, companyListIds = Model.???? })

A better option (based on comments from Tacud) which would require a smaller POST URL would be by returning a list of the id properties only which can then be applied to a query. But its still a list and still needs to be sent back without an index from and ActionLink. This will help keep track and allow me to continue drilling down to a smaller and smaller list.

Below is parts of my model class, the index Action from the controller, and the index view. Model namespace:

public class Company
{
    public int Id { get; set; }

    [Required]
    public string Name { get; set; }
    public string Address { get; set; }
    public string City { get; set; }
    public string State { get; set; }
}

Controller Namespace:

public async Task<IActionResult> Index(ICollection<int> prev, string orderBy , string searchCategory ="", string searchString = "")
    {
        List<string> Categories = new List<string>() { "Name", "City", "State", "Zip", "Contact Person" };
        ViewBag.searchCategory = new SelectList(Categories);
        ViewBag.sortByName = orderBy == null ? "name" : orderBy == "name" ? "namedesc" : "name";
        ViewBag.sortByCity = orderBy == "city" ? "citydesc" : "city";
        ViewBag.sortByState = orderBy == "state" ? "statedesc" : "state";
        ViewBag.companyIndex = companyList.Count==0 ? await _context.Company.ToListAsync() : companyList ;

        List<Company> resultSet = new List<Company>(ViewBag.companyIndex);

        if (!String.IsNullOrEmpty(searchCategory) && !String.IsNullOrEmpty(searchString))
        {
            switch (searchCategory)
            {
             .....
            }
        }

        switch (orderBy)
        {
          ....
        }

        return View(resultSet);
    }

View namespace:

@model IEnumerable<Laier_It.Models.Company> <p>
@using (Html.BeginForm() {
<p>
    Search By: @Html.DropDownList("SearchCategory", "")
    Search For: @Html.TextBox("SearchString")
    <input type="submit" value="Filter" />
</p> }
<table class="table ">
    <thead>
        <tr>
            <th>
                @Html.ActionLink("Name", "Index", new { orderBy = ViewBag.sortByName, companyList = Model })
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Address)
            </th>
            <th>
                @Html.ActionLink("City", "Index", new { orderBy = ViewBag.sortByCity, companyList = Model })
            </th>
            <th>
                @Html.ActionLink("State", "Index", new { orderBy = ViewBag.sortByState, companyList = Model })
            </th> </tr>
    </thead>
    <tbody>
        @foreach (var item in Model)
        {
            <tr>
                <td>
                    @Html.DisplayFor(modelItem => item.Name)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.Address)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.City)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.State)
                </td>  </tr>
        }
    </tbody>
</table>

回答1:

To first obtain the list of Id's that I want to post back to the controller of the current rendition showing within the WebAPI view page I used @Model.Select(x => x.Id)

My controller index method was only changed by this

var resultSet = prev.Count == 0 ? await _context.Company.ToListAsync() : 
               await _context.Company.Where(x => prev.Contains(x.Id)).ToListAsync();

And my View looks like this:

@model IEnumerable<Laier_It.Models.Company>

@using (Html.BeginForm() )
{
    <p>
        Search By: @Html.DropDownList("SearchCategory", "")
        Search For: @Html.TextBox("SearchString")
        <input type="submit" value="Filter" />
    </p>
}

<table class="table ">
    <thead>
        <tr>
            <th>
                @Html.ActionLink("Name", "Index", new { orderBy = ViewBag.sortByName, prev = @Model.Select(x => x.Id) } )
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Address)
            </th>
            <th>
                @Html.ActionLink("City", "Index", new { orderBy = ViewBag.sortByCity, prev = @Model.Select(x => x.Id) } )
            </th>
            <th>
                @Html.ActionLink("State", "Index", new { orderBy = ViewBag.sortByState, prev = @Model.Select(x => x.Id) } )
            </th>
        </tr>
    </thead>
    <tbody>
        @foreach (var item in Model)
        {
            <tr>
                <td>
                    @Html.DisplayFor(modelItem => item.Name)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.Address)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.City)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.State)
                </td>
            </tr>
        }
    </tbody>
</table>

来源：https://stackoverflow.com/questions/42983224/asp-net-passing-list-back-to-controller-from-ienumerable-model-inside-table-hea