SelectExtensions Class

The SelectExtensions class contains methods that extend the HtmlHelper class. Each extension method renders an HTML select element. The DropDownList method renders an element that enables the user to select an item from a drop-down list. The ListBox method renders an element that enables the user to select from a scrolling list of items.

The following example shows how to use both the DropDownList and ListBox methods in a view. The ListBox control displays a list of book titles, from which the user can select one or more books. The DropDownList displays a list of pets, from which the user can select one pet. The selections are then displayed in another view.

The following classes define the data model that is used for a book and a pet.

Public Class Book
    Private _Id As Integer
    Public Property Id() As Integer
        Get
            Return _Id
        End Get
        Set(ByVal value As Integer)
            _Id = value
        End Set
    End Property

    Private _Title As String
    Public Property Title() As String
        Get
            Return _Title
        End Get
        Set(ByVal value As String)
            _Title = value
        End Set
    End Property
End Class

Public Class Pet
    Private _Id As Integer
    Public Property Id() As Integer
        Get
            Return _Id
        End Get
        Set(ByVal value As Integer)
            _Id = value
        End Set
    End Property

    Private _Name As String
    Public Property Name() As String
        Get
            Return _Name
        End Get
        Set(ByVal value As String)
            _Name = value
        End Set
    End Property
End Class

In the following example, the list of items for each control is created in the Index action method and passed to the view in the ViewDataDictionary object.

The following example shows a view that displays the entry form that contains the list box and the drop-down list. The list box is passed an anonymous object that defines the HMTL size attribute for the rendered list box.

When the user submits the form, the Selection action method handles the request and renders the view that displays the selections.

The following view displays the user selections.

Reference

Other Resources