ARTICLE

Working With the DropDownList Control in ASP.NET MVC

Posted by Krishna Garad Articles | ASP.NET MVC January 30, 2012
In this article we will see how to use the DropDownList control in ASP.NET MVC.
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Introduction

In this article we will see how to use the DropDownList control in ASP.Net MVC. In a normal ASP.NET application we are all familiar with DropDown but as we moved to MVC we lost our favorite ASP.NET controls like DropDown, Gridview etc. In this article we will see how we can use our DropDownList control in ASP.Net MVC application.

In this article we will see a simple DropDown with only string text as items, simple DropDown with text as well as values, DropDown populated from database with text only, DropDown populated from db with id and text field, DropDown with some default values and DropDown with autopostback. So let's start working with DropDownList.

Simple DropDown with Select Tag(Text Only)

We can create simple DropDown list by using <select></select> tag of HTML with values like below.

<select name="Author">
<option>Krishna Garad</option>
<option>Vulpes</option>
<option>Arjun</option>
<option>Sonakshi</option>
<option>Monika</option>

Simple DropDown with Select Tag(text as well as value);

In the above we see a simple DropDownList which contains only text, not any value field. To create a DropDown with text as well as value use the following snippet.

 <select name="AuthorWithValue">
<option value="100">Krishna Garad</option>
<option value="110">Vulpes</option>
<option value="120">Arjun</option>
<option value="130">Sonakshi</option>
<option value="140">Monika</option>

Simple DropDown Populated From Database(with text only)

In many cases we need our DropDownList to be populated from a database. We can do that by populating the list of strings in our controller and then access each string from the list in our aspx page like below.

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.

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