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ashok kumar

ashok kumar

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Cascading Dropdownlist Using UpdatePanel

Jan 24 2013 9:23 PM
Cascading Dropdownlist Using UpdatePanel:

.aspx code:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="jquery-1.7.2.js" type="text/javascript"></script>
    <script src="JScript.js" type="text/javascript"></script>
</head>
<body>
    <form id="form1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server">
    </asp:ScriptManager>
    <div>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true"
                    onselectedindexchanged="DropDownList1_SelectedIndexChanged">
                </asp:DropDownList>
                <br />
                <br />
                <asp:DropDownList ID="DropDownList2" runat="server" AutoPostBack="true"
                    onselectedindexchanged="DropDownList2_SelectedIndexChanged">
                </asp:DropDownList>
                <br />
                <br />
                <asp:DropDownList ID="DropDownList3" runat="server" AutoPostBack="true"
                    onselectedindexchanged="DropDownList3_SelectedIndexChanged">
                </asp:DropDownList><br />
            </ContentTemplate>
        </asp:UpdatePanel>
    </div>
    </form>
</body>
</html>


.cs file:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;

public partial class Default2 : System.Web.UI.Page
{
    public SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["ArtSQLConnStr"]);
    DataSet dataSet1 = new DataSet();
    SqlDataAdapter da = null;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            da = new SqlDataAdapter("select * from student_test", conn);
            da.Fill(dataSet1);
            DropDownList1.DataSource = dataSet1;
            DropDownList1.DataTextField = "Test_toppic";
            DropDownList1.DataValueField = "Testid";
            DropDownList1.DataBind();
            DropDownList1.Items.Insert(0, new ListItem("Please select", "0"));
        }
    }
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        da = new SqlDataAdapter("select * from student_test", conn);
        da.Fill(dataSet1);
        DropDownList2.DataSource = dataSet1;
        DropDownList2.DataTextField = "Test_toppic";
        DropDownList2.DataValueField = "Testid";
        DropDownList2.DataBind();
        DropDownList2.Items.Insert(0, new ListItem("Please select", "0"));
        ScriptManager.RegisterStartupScript(UpdatePanel1, UpdatePanel1.GetType(), "Message", "<script>EnableDisableDropdownlist()</script>", false);
    }
    protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
    {
        da = new SqlDataAdapter("select * from student_test", conn);
        da.Fill(dataSet1);
        DropDownList3.DataSource = dataSet1;
        DropDownList3.DataTextField = "Test_toppic";
        DropDownList3.DataValueField = "Testid";
        DropDownList3.DataBind();
        DropDownList3.Items.Insert(0, new ListItem("Please select", "0"));
        ScriptManager.RegisterStartupScript(UpdatePanel1, UpdatePanel1.GetType(), "Message", "<script>EnableDisableDropdownlist()</script>", false);
    }
    protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e)
    {
        ScriptManager.RegisterStartupScript(UpdatePanel1, UpdatePanel1.GetType(), "Message", "<script>alert('3rd dropdownlist')</script>", false);

    }
}


JQuery code:

$(document).ready(function () {
    EnableDisableDropdownlist();
})

function EnableDisableDropdownlist()
{
    if ($("[ID$='DropDownList1']").val() == "0")
    {
        $("[ID$='DropDownList2']").attr("disabled", true);
        $("[ID$='DropDownList3']").attr("disabled", true);
    }
    else if ($("[ID$='DropDownList2']").val() == "0")
    {
        $("[ID$='DropDownList3']").attr("disabled", true);
    }
}



Answers (1)