将部分视图加载到div中仅一次

Question

I have the following controller and view:

SearchController.cs :

  public class SearchController : Controller
  {
    public ActionResult Index()
    {
      return View();
    }

    public ActionResult SearchResults()
    {
      int rnd = new Random().Next(100);
      var model = new List<SearchResultModel>
      {
        new SearchResultModel { Id=rnd, FirstName="Peter" + rnd, Surname="Pan" },
        new SearchResultModel { Id=rnd+1, FirstName="Jane", Surname="Doe"+rnd }
      };
      return PartialView("SearchResults", model);
    }
  }

Index.cshtml :

@model WebApplication1.Models.SearchCriterionModel

@{
  ViewBag.Title = "Index";
}

<script type="text/javascript">
  $(document).ready(function () {
    $('#btnSearch').click(function (evt) {
      evt.preventDefault();
      $('#placeholder').load("/Search/SearchResults");
    })
  });
</script>

<button id="btnSearch">Search</button>
<div id="placeholder"></div>

I just figured out that the template I used for the view (the standard Edit template) inserted a Html.BeginForm which somehow didn't let me fill a partial view into my div . So I removed the clutter and tried 'from scratch' and look - it worked. I can now successfully load the partial view SearchResults into the div with id = placeholder .

But: this only works once. That is, on the first button click, the code-behind method SearchResults() is called and the div is filled with the first set of 'randomized' data. Clicking more than once does enter the client-side click method, but doesn't go into my SearchResults() method anymore, so I guess no post-back is happening!? Why is that so? And how can I 'fix' this, that is, learn how to do it right and get new data everytime I press the button?

Answer 1

My MVC is a bit rusty, but you could try adding a random number to the URL so the browser won't get it from cache. Not sure if the controller method will ignore the 'r' parameter or not.

<script type="text/javascript">
   $(document).ready(function () {
     $('#btnSearch').click(function (evt) {
       evt.preventDefault();
       var random = getRandomNumber();  //TODO: implement
       $('#placeholder').load("/Search/SearchResults?r=" + random);
     })
   });
</script>

Answer 2

For completion's sake, this is how I ended up doing it.

First, I used a form because I wanted to pass parameters to the action method in the controller, similar to this:

@using(Html.BeginForm())
{
  .
  .
  some input elements
  .
  .
  <input type="submit" value="Search" />
}

Then I used the following script. Note that for this to work the action method now has to take an instance of the ViewModel as parameter as well.

<script type="text/javascript">
  $(document).ready(function () {
    $("form").submit(function () {
      var model = $(this).serialize();
      $.ajax({
        url: '@Url.Action("SearchResults", "Search")',
        data: model,
        cache: false,
        dataType: "html",
        success: function (response) {
          $("#placeholder").html(response);
        }
      });
      return false;
    })
  });
</script>