MVC 3 dropdownfor populated but cannot get user's selection - asp.net-mvc-3

I'm new to MVC 3. I want 3 dropdown lists. The user picks an item from each list and then retrieves the selections based on the matches. For my problem I'm just using 2 dropdowns and code snippets. I have all 3 dropdowns populated - the first two from Linq to Sql and the 3rd is an option list created with Razor (A-Z).
I'm missing the step of setting the values of what was chosen into MemberSetup.SelectedProgramID and MemberSetup.SelectedOrganizationID. I'd like the text stored in MemberSetup.SelectedProgramName and MemberSetup.SelectedOrganizationName respectively. I think if I can get the selected ids into the model, I can pass them through ActionLink and not deal with #Html.Hidden variables. However, no matter what is selection the model SelectedProgramID and SelectedOrganizationID are zero (expect 1, 2, 3 or 4 for Program ID and 1, 2, 5, or 6 for Organization ID).
Any help / corrections would be appreciated.
Model:
{
public int SelectedProgramID { get; set; }
public string SelectedProgramName {
get { return this._myProgramName; }
set { this._myProgramName = value; }
}
public IEnumerable<SelectListItem> ProgramList { get; set; }
public int SelectedOrganizationID { get; set; }
public string SelectedOrganizationName
{
get { return this._myOrganizationName; }
set { this._myOrganizationName = value; }
}
public IEnumerable<SelectListItem> OrganizationList { get; set; }
}
Controller:
{
var db = new STARDataContext();
MemberSetup setupModel = new MemberSetup();
setupModel.ProgramList = db.ProgramAlls.ToList()
.Select(p => new SelectListItem
{
Value = p.ProgramID.ToString(),
Text = p.ProgramName.ToString()
});
setupModel.OrganizationList = db.AreaAlls.ToList()
.Select(p => new SelectListItem
{
Value = p.AreaID.ToString(),
Text = p.AreaName.ToString()
});
return View(setupModel);
}
View:
{
#using ( Html.BeginForm() ) {
#Html.DropDownListFor(model => model.SelectedProgramID, Model.ProgramList)
#Html.DropDownListFor(model => model.SelectedOrganizationID, Model.OrganizationList, "Please select Organization", new { #class = "DropDownList" } )
#Html.Hidden("SelectedProgramID", Model.SelectedProgramID)
#Html.Hidden("SelectedProgramName", Model.SelectedProgramName)
#Html.Hidden("SelectedOrganizationID", Model.SelectedOrganizationID)
#Html.Hidden("SelectedOrganizationName", Model.SelectedOrganizationName)
#Html.ActionLink("Get Members", "Select", new {programID=Model.SelectedProgramID,orgID=Model.SelectedOrganizationID })
}
}

use hiddenFor instead of hidden,so your syntax should look like this
#Html.HiddenFor(a=>a.SelectedProgramName)
Since you have SelectedProgramID and SelectedOrganizationID defined, you won't need to use hidden field for it. To construct the dropdown, you should do something like this
Html.DropDownListFor(x=>x.ID,
new SelectList(Model.Products,"ID", "Sku", Model.ID), " select ")
For your reference: Use Html.DropDownListFor to get a selected value

The above class, controller and view are correct for presenting the drop-downs. This is why I was perplexed.
However, I had the SelectMember in the Get section. [HttpPost] and SelectMember can see what was selected.

Related

How to keep DropDownList values between a server call in ASP.NET MVC3

I have an ASP.NET MVC3 application. I have the following ViewModel:
public class MyViewModel
{
public string Year { get; set; }
public string Month {get; set; }
public IEnumerable<SelectListItem> Years
{
get
{
return Enumerable.Range(2000, DateTime.Now.Year - 2000).Select(x => new SelectListItem
{
Value = x.ToString(),
Text = x.ToString()
});
}
}
}
And the following View:
#model MyNamespace.MyViewModel
#Html.DropDownListFor(
x => x.Year,
new SelectList(Model.Years, "Value", "Text"),
"-- select year --"
)
#Html.DropDownListFor(
x => x.Month,
Enumerable.Empty<SelectListItem>(),
"-- select month --"
)
I fill the DropDownList for Month with a jQuery function that is triggered onchange from the DropDownList for Year, which works perfectly. When the form is posted to the server and then the view is rendered back I want to keep the values in the 'Month' DropDownList as it happens correctly for Year. Therefore I tried (besides the jQuery script):
public class MyViewModel
{
public string Year { get; set; }
public string Month {get; set; }
public IEnumerable<SelectListItem> Months
{
get
{
if(Year != null)
{
return Enumerable.Range(1, 12).Select(x => new SelectListItem
{
Value = x.ToString(),
Text = x.ToString()
});
}
}
}
And in the View:
#Html.DropDownListFor(
x => x.Month,
new SelectList(Model.Months, "Value", "Text"),
"-- select month --"
)
I left Years out of the code to make things shorter. This code throws a NullReferenceException at the first run because the IEnumerable is empty. how can I achieve my goal?
You have to repopulate the month list in your action.
The POST is stateless is not like asp.net webforms.
Just do something like this in your code:
public ViewResult MyAction(MyViewModel model)
{
if (ModelState.IsValid)
{
//.. do your stuff ...
//return redirect to index if everything went ok
}
//something went wrong return the model
model.Years = new SelectList(/* code to populate years */, "Value", "Text", Model.Year);
model.Months = new SelectList(/* code to populate months */, "Value", "Text", Model.Month);
}
As a side note I prefer to use SelectList instead of IEnumerable<SelectListItem> beacuse I can set the default value in the controller (a better fit for the controller responsibility in my opinion) and not in the View.

MVC3 DropDownListFor not populating selectedValue

I feel like I'm taking crazy pills. I have a dropdownlist for a view that reads from our database all of the wine producers we have. I want to set the selectedValue to a particular ID driven by the referring page. I can see it picks up the selectedValue in debug, I see the selected value populated (906 for this example), but it doesn't set the dropdownlist to the correct value when the page is rendered, it always defaults to 1 for the default value. I've tried creating the selectList in razor as opposed to my controller, but nothing works. Any help on this would be appreciated, I'm guessing it is something small.
Controller:
if (User.IsInRole("admin"))
{
if (ID != 0)
{
ViewBag.ProducerSelect = new SelectList(db.Producers.OrderBy(p => p.Name), "ProducerID", "Name", ID);
}
else
{
ViewBag.ProducerSelect = new SelectList(db.Producers.OrderBy(p => p.Name), "ProducerID", "Name");
}
}
View:
if (User.IsInRole("producereditor"))
{
<h3>#ViewBag.ProducerName</h3>
}
else
{
<div class="editor-label">
#Html.LabelFor(m => m.Wine.ProducerID, "Producer")
</div>
<div class="editor-field">
#Html.DropDownListFor(m => m.Wine.ProducerID, ViewBag.ProducerSelect as SelectList)
</div>
}
Tried the below but no success:
ViewBag.ProducerSelect = new SelectList(from p in db.Producers
orderby p.Name
select new { p.ProducerID, p.Name }
, "ProducerID", "Name", ID);
If you want to preselect an item, You set that value to your ProducerId property.
var yourViewModelObj=new YourViewModel;
yourViewModelObj.Wine.ProducerId=906; //or whatever value you want
return View(yourViewModelObj);
Suggestion : For better code readablity/Maintenance, Try to avoid ViewBag / ViewData and use a ViewModel to pass the data.
I would add a Property to my ViewModel to hold the Collection of Producers
public class WineViewModel
{
//Other Existing properties also
public IEnumerable<SelectListItem> Producers{ get; set; }
public string SelectedProducer { get; set; }
}
Then in yout GetAction method, you can set the value like this, If you want to set one select option as the default selected one.
public ActionResult CreateWine()
{
var vm=new WineViewModel();
//The below code is hardcoded for demo. you mat replace with DB data.
vm.Producers= new[]
{
new SelectListItem { Value = "1", Text = "Prodcer A" },
new SelectListItem { Value = "2", Text = "Prodcer B" },
new SelectListItem { Value = "3", Text = "Prodcer C" }
};
//Now let's set the default one's value
vm.SelectedProducer = "2";
return View(vm);
}
And in your Strongly typed View,
#Html.DropDownListFor(x => x.SelectedProducer,
new SelectList(Model.Producers, "Value", "Text"), "Select Producer")
The HTML Markup generated by above code will have the HTML select with the option with value 2 as selected one.
I figured this out. I had ViewModel.wine.ProducerID elsewhere on the page in a hidden field, and that defaults to 1, so I just assigned that to passed in value, and it worked great. I knew it was something like that. Thanks!
User a ViewModel ex WineViewModel
public class WineViewModel
{
public Wine Wine { get; set; }
public SelectList PProducerList { get; set; }
public WineViewModel() { }
public WineViewModel(Wine wine)
{
this.Wine = wine;
}
}
Try the following in your controller
var model = new WineViewModel( selectwine);
model.ProjectTypeList = new SelectList( from p in db.Producers
orderby p.Name
select new { p.ID, p.Name }, "ID", "Name")
notice how I am exclusively declaring which is the ID and which is the Value in my SelectList
Then in your view do
#Html.DropDownListFor(model => model.Wine.ProducerID, Model.ProjectTypeList)

drop down list in mvc 3

Hey friends I am using drop down list in my mvc 3 project. Here the user choose one of the options and save it. And when he/she revisit the page than i have to make the initially saved value as selected value. Actually i am doing this with custom html helper as per need. But i am getting problem on it. I am doing this as:
else if (question_type == 7)
{
EAI.DAL.EaiEntities entities = new DAL.EaiEntities();
QuestionnaireRepository repository = new QuestionnaireRepository(entities);
SelectList typesList = repository.PopDdlList(qid);
output.Append(helper.Label(questiontext));
if (answer == "")
{
output.Append(helper.DropDownList("ddl" + question_id, typesList, "-- select type----));
}
else
{
output.Append(helper.DropDownList("ddl" + question_id, typesList, answer));
}
return helper.Raw(output.ToString());
}
Actually above code renders the selected value from database but it actually replacing the "-- select type ---" . So, After saving once if i visit the same page and save the page than i can get empty value in Formcollection.
So, please suggest the appropriate way of doing this
I usually add a few properties in my model:
int SelectedCategory { get; set; }
IEnumerable<SelectListItem> Categories { get; private set; }
and then load the data in my model constructor:
ProductService productService = new ProductService();
this.Categories =
productService.GetCategories()
.Select(c => new SelectListItem() { Text = c.Name, Id = c.Id.ToString() });
this.Categories.InsertAt(0, new SelectListItem() { Text = "--- Please Select ---", value = "" });
then in my Razor markup do something like:
#Html.DropDownListFor(m => m.SelectedCategory, Model.Categories)
This should auto wire up in the standard MVC way. Hope this helps.

How do you properly create a MultiSelect <select> using the DropdownList helper?

(sorry, there are several item here but none seems to allow me to get this working.)
I want to create a DropDownList which allows multiple selection. I am able to populate the list but I can't get the currently selected values to seem to work.
I have the following in my controller:
ViewBag.PropertyGroups = from g in db.eFinGroups
where g.GroupType.Contents == "P"
select new
{
Key = g.Key,
Value = g.Description,
Selected = true
};
ViewBag.SelectedPropertyGroups = from g in company.Entities
.First().Properties.First().PropertyGroups
select new {
g.eFinGroup.Key,
Value = g.eFinGroup.Description };
In the view I have:
#Html.DropDownListFor(model => model.PropertyGroupsX,
new MultiSelectList(ViewBag.PropertyGroups
, "Key", "Value"
, ViewBag.SelectedPropertyGroups),
new { #class = "chzn-select", data_placeholder = "Choose a Property Group", multiple = "multiple", style = "width:350px;" })
PropertyGroupX is a string[] in the model.
I have tried all types of iterations with the selected properties... passing just the value, just the key, both, etc.
Also, what type is PropertyGroupX supposed to be? Is string array correct? Or should it be a dictionary that contains the current propertygroups? I really am having a hard time finding doc on this.
Someone suggested I should be using ListBoxFor. I have changed to that and still have the same issue. The selected values are not being set as selected when the option tags are rendered. Here is what I have tried:
#Html.ListBoxFor(model => model.PropertyGroups, new MultiSelectList(ViewBag.PropertyGroups, "Key", "Value"))
I have tried the model.PropertyGroups as a collection of string matching the Values, as a collection of Guid matching this IDs and as an anonymous type with both a Key and Value to match the items in the ViewBag. Nothing seems to work.
You don't use DropDownListFor if you want to create a multiselect list. You use the ListBoxFor helper.
View model:
public class MyViewModel
{
public string[] SelectedIds { get; set; }
public IEnumerable<SelectListItem> Items { get; set; }
}
Controller:
public ActionResult Index()
{
var model = new MyViewModel
{
// preselect the first and the third item given their ids
SelectedIds = new[] { "1", "3" },
// fetch the items from some data source
Items = Enumerable.Range(1, 5).Select(x => new SelectListItem
{
Value = x.ToString(),
Text = "item " + x
})
};
return View(model);
}
View:
#model MyViewModel
#Html.ListBoxFor(x => x.SelectedIds, Model.Items)

When using DropDownListFor how do I bind the SelectList to the Model

This page works in two steps,
Step 1 - The user hits Index() and the SelectList is populated with the applications from the databse.
Step 2 - they select an applicaiton from the list, which posts the page back, which reloads the page with the application Details added
Error: When I run this and get to step 2, I get an error back saying:
The ViewData item that has the key 'ApplicationId' is of type 'System.Int32' but must be of type 'IEnumerable'.
This appears to be because the Model.ApplicationList is now null as it hasn't bound back to the model when the form was posted, can I make it do this?
View:
#using (Html.BeginForm())
{
#Html.DropDownListFor(x => x.ApplicationId, Model.ApplicationList, "Select an Application" , new { #onchange = "this.form.submit();" })
}
Model:
public class IndexModel
{
public int ApplicationId { get; set; }
public List<SelectListItem> ApplicationList { get; set; }
public string Detail { get; set}
}
Controller:
public ActionResult Index()
{
using (var dc = new Entities())
{
var model = new IndexModel();
model.ApplicationList = new List<SelectListItem>();
var applications = dc.Applications.OrderBy(a => a.Name).ToList();
foreach (var application in applications)
{
model.ApplicationList.Add(new SelectListItem
{
Selected = false,
Text = application.Name,
Value = application.Id.ToString()
});
}
model.ApplicationId = 1;
return View(model);
}
}
[HttpPost]
public ActionResult Index(IndexModel model)
{
model.Detail = GetDetail(model.ApplicationId);
return View(model);
}
I was struggling with the same problem. It doesn't look like .net mvc3 lets you do this without the help of jquery. Drop down lists will get their selected item bound to the model when posting but not all the items in the combo box. You would have to rebuild it each time you pass the viewmodel back to the view.
Another way around losing the dropdown list is to use ajax.

Resources