CODEWITHSUNDEEP
asp.net-mvc
phosplait
phosplait

Reputation: 295

MVC MultiSelectList default value ignored

I am trying to create a multiselect list and specify the default values for the dropdown, but the default values I am providing are being ignored.

My controller looks like this:

var ProvisionFromDb = (from Provision in db.Provisions
                      orderby Provision.Provision1 ascending
                      select new SelectListItem
                          {
                              //select all items
                              Selected = true,
                              Text = Provision.AltDescription,
                              Value = Provision.Provision1.ToString()
                          }).ToList();
ViewBag.ProvisionDropdown = new MultiSelectList(ProvisionFromDb, "Value", "Text");

In my view, I have the following statement:

@Html.ListBox("ProvisionId", (MultiSelectList)ViewBag.ProvisionDropdown)

Everything works, except for the default values not being selected. I assume this is because of MultiSelectList not recognizing the selected property in the SelectList objects. What is the simplest way to correct this?

Additional info: In the razor view statement, "ProvisionId" represents the name/ID of the select dropdown that is being created.

Upvotes: 2

Views: 1811

Answers (2)

phosplait
phosplait

Reputation: 295

The solution here was to put the defaults into an overloaded MultiSelectList constructor, where the 4th parameter is an array representing values of the default selected items.

In my case, I did not need to define a model. The following worked:

ViewBag.ProvisionDropdown = new MultiSelectList(ProvisionFromDb, "Value", "Text", new[] {"Selected Value1","Selected Value2"});

A linq query could have also been used to generate this array based on the "Selected" property of SelectListItem.

Upvotes: 3

Chris Pratt
Chris Pratt

Reputation: 239430

The options rendered as selected are determined by the value of what you're binding to. Here, namely, "ProvisionId". If that's a property on your model, you should use ListBoxFor instead and then set it to the list of Provision1 values you want to be selected. If it's not a property on your model, you can set something like ViewBag.ProvisionId with that list.

Upvotes: 1

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