trying to set a dropdown in MVC

Question

I almost have this solved but need a little push.

Here's what I have:

In the database I have a field called active that is a bit field (True/False)

I have placed a dropdownlist on the View form like this:

<%= Html.DropDownList("lstActive", new SelectList((IEnumerable)ViewData["ActiveList"])) %>

In my controller, I simply have this code to generate the True/False in the dropdown:

        List<string> activeList = new List<string>();
        activeList.Add("True");
        activeList.Add("False");

        ViewData["ActiveList"] = new SelectList(activeList);

I want to bind to the field in the database called active and select it in the dropdown. When I view it like this I get this:

So the questions are these:

Obviously I am not pointing to the Value and Text property but what is that in this case? And how do I select the value that is in the database?

Any help would be appreciated.

Answer 1

This should clarify:

Drop-down Lists and ASP.NET MVC

For each select list element you need to set the Text and Value properties...

Answer 2

Here's a couple of suggestions for you.

First, your DropdownList's name is "lstActive", so if you create a List<SelectListItem> called "lstActive" and pass that back in ViewData, you don't have to do anything fancy with boxing. Then your declaration looks like:

<%= Html.DropDownList("lstActive") %>

easy, huh?

In your controller, you create your List. Here's a method I've used:

    private List<SelectListItem> GetAccounts(User user)
    {
        var items = new List<SelectListItem>();
        foreach (Account account in user.Accounts)
        {
            var item = new SelectListItem();
            item.Text = account.Name;
            item.Value = account.AccountId.ToString();
            if (ActiveAccount == account.AccountId)
                item.Selected = true;
            items.Add(item);
        }
        return items;
    }

Basically, what I'm trying to point out is that you can set a property on your SelectListItem that you wish to be displayed as selected. Here, I'm using my own code for Users and Accounts, but you'd substitute your own data based on your db query.

Answer 3

First thing, you're recreating a SelectList the ViewData data, you should declare the DropBox as follows:

<%= Html.DropDownList("lstActive", ViewData["ActiveList"]) %>

Second, instead of creating a generic list on the controller, create a SelectList and add SelectListItems to it:

var activeList = new SelectList 
{
  new SelectListItem { Text = "True", Value = true },
  new SelectListItem { Text = "False", Value = false }
};

ViewData["ActiveList"] = activeList;

Answer 4

First, this is probably better suited to radio buttons, not a select. Second, you really ought to have a view model with a property that is an IEnumerable<SelectListItem> that supplies the values for the select. You can construct that directly in the model.

 var model = new ViewModel();
 model.ActiveList = new List<SelectListItem>
                    {
                        new SelectListItem { Text = "Yes", Value = "true" },
                        new SelectListITem { Text = "No", Value = "false" }
                    };
 model.Active = false; // this will be the default

 return View( model );

Then in your view (strongly-typed to your view model type):

 <%= Html.DropDownListFor( m => m.Active, Model.ActiveList ) %>

Using radio buttons, you can omit the list (since there are only the two choices).

 <%= Html.RadioButtonFor( m => m.Active, true ) %> Yes
 <%= Html.RadioButtonFor( m => m.Active, false ) %> No

Answer 5

One solution could be as follows:

Model:

public class NameValue
{
    public string Name { get; set; }
    public string Value { get; set; }
}

Controller:

string currentActiveValue = myDB.active.ToString(); 
List<NameValue> yesNoList = new List<NameValue> 
                   {      
                        new NameValue { Name = "Yes", Value = "True" },      
                        new NameValue { Name = "No", Value = "False" }      
                   };   

SelectList myActiveList = new SelectList(yesNoList, "Name", "Value", currentActiveValue);
ViewData["ActiveList"] = myActiveList;

View:

div>Is Active: <%= Html.DropDownList("ActiveList") %></div>