Working With the DropDownList Control in ASP.NET MVC

In controller

cscEntities entity = new cscEntities();
var x = (from n in entity.Authors select n);
List<string> items = new List<string>();

foreach (var item in x)
{
items.Add(item.Name);
}

ViewBag.Authors = items;

In View

<select name="AuthorFromDB">
<%foreach (var item in ViewBag.Authors)
{%>

<option><%=item%></option>
<%} %>

</select>

DropDownList without Select Tag

We can create a DropDown without using the select tag which is populated from the database like below.

In Controller

var db = new cscEntities();
var query = db.Authors.Select(c => new { c.AuthorId, c.Name });
ViewBag.Authors1 = new SelectList(query.AsEnumerable(), "AuthorId", "Name");

In View

<%= Html.DropDownList("Authors1", (IEnumerable<SelectListItem>)ViewBag.Authors1)%>

DropDown with Default Value

Many times we have a requirement to keep some default values and then populate the DropDown from the database.

<%= Html.DropDownList("Authors1", (IEnumerable<SelectListItem>)ViewBag.Authors1, "--Select Author--")%>

DropDown with Autopostback

Still now we have seen DropDownList creation but an important event of a DropDown we all know i.e. autopostback in ASP.Net application by setting Autopostback true we can make our DropDown capable of doing a post back in MVC we can't. In MVC we can do it in the following way.

<% using (Html.BeginForm("Index", "Home", FormMethod.Post, new { id = "Form1" }))
{%>
<%= Html.DropDownList("Authors1", (IEnumerable<SelectListItem>)ViewBag.Authors1, "--Select Author--", new { onchange = "document.getElementById('Form1').submit();" })%>
<%} %>

Conclusion

In this way we can use our favorite DropDownList control in ASP.NET MVC application with postback and default values as well as populating from a database.