ASP.NET MVC 2 DropDownList Selected item changed? - asp.net-mvc

I have a drop down list on my aspx form and what I want is to refresh the site after I select an item from the list. This is my drop down list:
<%: Html.DropDownListFor(x => x.CompanyUserFilterId, new SelectList(Model.CompanyUsers, "Id", "FirstName", Model.CompanyUserFilterId))%>
I use it to filter the data shown on the form depending on the selected item on the drop down list. Please help :)

you'll need to 'refresh' the site with some sort of client side mechanism onchange. A similar solution using JQuery is posted here.

The simplest method is probably to trigger an html/javascript onchange-event, and handle that to update your page (or post the form with the selected Id).
Take a look at this: http://blog.wekeroad.com/2008/10/21/asp-net-mvc-dropdownlist-and-html-attributes

Related

Asp.net MVC DropDownList Add and Update

I am quite new to this as my background is ASP.net Web Form. I am faces with 3 issues as followed:
Dropdownlist postback and other dropdownlist is showen once the user selected the 1st dropdownlist.
2nd, I am trying to pass the dropdownlist selected value in adding data
#Html.DropDownList("CategoryID", ViewData["Category"] as List)
I am trying to update the data based on the selectedvalue
#Html.DropDownList("CategoryID", ViewData["Category"] as List)
I am able to populate it from the database.
Any advice would be helpful. Many thanks
The answer to this question is
#Html.DropDownListFor(model=> model.CategoryID, ViewData["Category"] as List<SelectListItem>)
and you use FormMethod.Post

MVC Dropdown lists bound depending on the value of another dropdown list

I am trying to write an MVC webpage that has two drop down lists. The content of the second list depends on what is selected in the first.
There does not seem to be a definitive way of doing this using built in MVC functions so I am going to have to roll my own. However I am not clear on the best way of getting all the functionality I require... which is "be the same as webforms" :)
I have created the dropdowns in a way similar to this
However I am not sure how to develop this so that if there is a 'selected' element in the first list when it is first bound this will flow through to automatically binding the second list on page load.
Edit:
Just to be clear I have the ability to bind the filtered list to the second dropdown. However if my Model contains a selection for the first dropdown the selection is set correctly but the second dropdown list does not fill.
(do I have to state I am newish to MVC and Javascript is like some alien language to me?)
Edit2:
I have thought about this a bit more.
Clearly I am strongly influenced by my time developing webforms and I don't quite 'get' MVC yet.
I think that really I have some things I should be catching in my model (ie if I already have the info to set the two dropdowns then I should in some way catch that in the controller and build the dropdowns pre set. Rather than trying to build an "ondatabound" type method and have the view call that (which was my initial intent)... Now I need to go and work out how to do that :)
This is one of the better implementations that I found. The question has also been discussed here.
You task contains 3 subtasks:
You should ajax get list of items for second ddl on changing selection of first ddl by using selected value
You should process action of getting list of items for 2-nd ddl by your Controller and return View with defined content of second ddl
You should update content of second ddl by getting result of processed action
<script type="text/javascript">
$(function(){
$("form #ddl_1").change(function(){
$.get({ // get request
url: "#Url.Action("MyController", "GetList"})" + "/" + $(this).val,
success: function(data){ // updating
$("form #ddl_2").html(data);
}
})
});
</script>
"GetList" action should take parameter "id" if you use default routes table (or you need to create special record at routes table with custom) and return partial view (without master page) with list of options for your ddl2, like this:
<option value="1">First</option>
<option selected value="2">Second</option>
<option value="3">Third</option>
See this blog post for creating cascading dropdown lists in asp.net mvc with downloadable source code.

Dropdownlist selected item not getting displayed in Asp.net MVC

I have implemented dropdown list in asp.net mvc using following code
In controller
int iSelectedNode=2;
ViewData["ddlModels"] = new SelectList(Models, "ModelCode", "ModelName", iSelectedNode);
In View
<%= Html.DropDownList("ModelCode", (SelectList)ViewData["ddlModels"],"--Select--", new {id="ddlModel" })%>
Still all the time i get to see text "--Select--" selected all the time.
Thanks in advance.
Make sure that your Models collection in the controller contains an element with ModelCode = 2.
This being said as you've tagged your question with asp.net-mvc-2 checkout this answer for a better way to handle drop down lists using strongly typed views and helpers.

MVC Paging and Sorting Patterns: How to Page or Sort Re-Using Form Criteria

What is the best ASP.NET MVC pattern for paging data when the data is filtered by form criteria?
This question is similar to: Preserve data in .net mvc but surely there is a better answer?
Currently, when I click the search button this action is called:
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Search(MemberSearchForm formSp, int? pageIndex, string sortExpression)
{}
That is perfect for the initial display of the results in the table.
But I want to have page number links or sort expression links re-post the current form data (the user entered it the first time - persisted because it is returned as viewdata), along with extra route params 'pageIndex' or 'sortExpression',
Can an ActionLink or RouteLink (which I would use for page numbers) post the form to the url they specify?
<%= Html.RouteLink("page 2", "MemberSearch", new { pageIndex = 1 })%>
At the moment they just do a basic redirect and do not post the form values so the search page loads fresh.
In regular old web forms I used to persist the search params (MemberSearchForm) in the ViewState and have a GridView paging or sorting event reuse it.
One possible solution is to attach a javascript click handler to the pager links that will submit the form by updating a hidden field containing the page number. This way you will get all the search criteria in the controller action.
Another possibility is to transform those pager links into submit buttons and place them inside the form.
A third possibility is to use the Session to persist search criteria.
You could perform a GET instead of a POST. if your request is to return search results, a GET might make more sense anyway. The benifit would be that all of your search fields are encoded into the URL. So, when you perform a page or sort on th exisiting URL, your data is perserved.
I have an example that using the MvcContrib Grid and Pager here:
http://weblogs.asp.net/rajbk/archive/2010/05/08/asp-net-mvc-paging-sorting-filtering-using-the-mvccontrib-grid-and-pager.aspx

MVC Index page and filter

This seems like a very simple question, but I'm getting lost, and need a few pointers.
I am using ASP.NET MVC C#, and have an Index page which displays a list of items, which is working fine.
Now I'm trying to add a DropDownList that depending on what the user selects will filter the list of items. But I keep thinking how you would do this in ASP.NET Web with RunAt Server, which I know is wrong.
Any pointers would be welcomed.
Put the select box in a form and make the form post back to a filter method in your controller.
Or
If you want to use ajax, use an Ajax.ActionLink to update the table with the filtered results
<% Ajax.ActionLink("Filter", "FilterMethod", null, new AjaxOptions { UpdateTargetId = "tableId" }, new { Title = "Filter results" }) %>
<table id="tableId"> .... </table>
Where "FilterMethod" is in yo0ur controller
This might help.
Also worth looking at:
http://jerrytech.blogspot.com/2009/06/implement-ajax-form-in-mvc-framework.html

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