Bind data to DropDownList in ASP.NET using VB.NET

The following code shows how to bind a DropDownList control.
  • 3808

The following code explains you how to create a DropDownList control through data binding.

Code for the Default.aspx

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "">



    <form id="Form1" runat="server">


            DropDownList Data Binding Example


        Select a background color for days in the calendar.



        <asp:Calendar ID="Calendar1" ShowGridLines="True" ShowTitle="True" runat="server" />



        <table cellpadding="5">



                    Background color:





                    <asp:DropDownList ID="DropDownColors" AutoPostBack="True" OnSelectedIndexChanged="Selection_Change"

                        runat="server" />







Code for Default.aspx.vb


Imports System.Data

Partial Class _Default

    Inherits System.Web.UI.Page

    Sub Selection_Change(ByVal sender As Object, ByVal e As EventArgs)


        ' Here we set the background color for days in the Calendar control

        ' based on the value selected in the DropDownList control.

        Calendar1.DayStyle.BackColor = _



    End Sub


    Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load


        ' Load data for the DropDownList control only once, when the

        ' page is first loaded.

        If Not IsPostBack Then


            ' These few lines for Specify the data source and field names for the Text

            ' and Value properties of the items in the DropDownList control.

            DropDownColors.DataSource = CreateDataSource()

            DropDownColors.DataTextField = "ColorListTextField"

            DropDownColors.DataValueField = "ColorListValueField"


            ' Bind the data to the control.



            ' Set the default selected item, if desired.

            DropDownColors.SelectedIndex = 0


        End If


    End Sub


    Function CreateDataSource() As ICollection


        ' Create a table to store data for the DropDownList control.

        Dim dt As DataTable = New DataTable()


        ' Define the columns of the table.

        dt.Columns.Add(New DataColumn("ColorListTextField", GetType(String)))

        dt.Columns.Add(New DataColumn("ColorListValueField", GetType(String)))


        ' Populate the table with sample values.

        dt.Rows.Add(CreateRow("Black", "Black", dt))

        dt.Rows.Add(CreateRow("Silver", "Silver", dt))

        dt.Rows.Add(CreateRow("White", "White", dt))

        dt.Rows.Add(CreateRow("Blue", "Blue", dt))

        dt.Rows.Add(CreateRow("Yellow", "Yellow", dt))


        ' Create a DataView from the DataTable to act as the data source

        ' for the DropDownList control.

        Dim dv As DataView = New DataView(dt)

        Return dv


    End Function


    Function CreateRow(ByVal Text As String, ByVal Value As String, ByVal dt As DataTable) As DataRow


        ' Create a DataRow using the DataTable defined in the

        ' CreateDataSource method.

        Dim dr As DataRow = dt.NewRow()

        dr(0) = Text

        dr(1) = Value


        Return dr


  End Function

End Class


More Articles

© 2013 dotNetheaven. All rights reserved.