Pass Cascading Autocomplete TextBoxes id to Like query using C# and VB.Net in ASP.Net

Hi swathiyemp,

Refer below sample.

HTML

<table border="0" cellpadding="0" cellspacing="5">
    <tr>
        <td>Country</td>
        <td>
            <asp:TextBox ID="txtCountry" runat="server" />
            <asp:HiddenField ID="hfCountry" runat="server" />
        </td>
    </tr>
    <tr>
        <td>State</td>
        <td>
            <asp:TextBox ID="txtState" runat="server" Enabled="false" />
            <asp:HiddenField ID="hfState" runat="server" />
        </td>
    </tr>
    <tr>
        <td>City</td>
        <td>
            <asp:TextBox ID="txtCity" runat="server" Enabled="false" />
            <asp:HiddenField ID="hfCity" runat="server" />
        </td>
    </tr>
    <tr>
        <td></td>
        <td><asp:Button ID="btnSubmit" Text="Submit" runat="server" OnClick="Submit" /></td>
    </tr>
</table>
<script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.10.0.min.js" type="text/javascript"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.9.2/jquery-ui.min.js" type="text/javascript"></script>
<link href="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.9.2/themes/blitzer/jquery-ui.css"
    rel="Stylesheet" type="text/css" />
<script type="text/javascript">
    $(function () {
        $("[id$=txtCountry]").autocomplete({
            source: function (request, response) {
                AjaxCall("CS.aspx/GetCountries", request.term, 0, response)
            },
            select: function (e, i) {
                $("[id$=hfCountry]").val(i.item.val);
                $("[id$=txtState]").removeAttr("disabled");
                $("[id$=txtState]").focus();
            },
            minLength: 1
        });

        $("[id$=txtState]").autocomplete({
            source: function (request, response) {
                AjaxCall("CS.aspx/GetStates", request.term, $("[id$=hfCountry]").val(), response)
            },
            select: function (e, i) {
                $("[id$=hfState]").val(i.item.val);
                $("[id$=txtCity]").removeAttr("disabled");
                $("[id$=txtCity]").focus();
            },
            minLength: 1
        });

        $("[id$=txtCity]").autocomplete({
            source: function (request, response) {
                AjaxCall("CS.aspx/GetCities", request.term, $("[id$=hfState]").val(), response)
            },
            select: function (e, i) {
                $("[id$=hfCity]").val(i.item.val);
            },
            minLength: 1
        });
    });

    function AjaxCall(url, prefix, parentId, response) {
        $.ajax({
            url: url,
            data: "{ 'prefix': '" + prefix + "', parentId: " + parentId + "}",
            dataType: "json",
            type: "POST",
            contentType: "application/json; charset=utf-8",
            success: function (r) {
                response($.map(r.d, function (item) {
                    return {
                        label: item.split('-')[0],
                        val: item.split('-')[1]
                    }
                }))
            },
            error: function (r) {
                alert(r.responseText);
            },
            failure: function (r) {
                alert(r.responseText);
            }
        });
    } 
</script>

Namespaces

C#

using System.Web.Services;
using System.Configuration;
using System.Data.SqlClient;

VB.Net

Imports System.Web.Services
Imports System.Configuration
Imports System.Data.SqlClient

Code

C#

[WebMethod]
public static string[] GetCountries(string prefix, int parentId)
{
    SqlCommand cmd = new SqlCommand();
    string query = "SELECT CountryId, CountryName FROM Countries WHERE CountryName LIKE + '%' + @Prefix + '%'";
    cmd.Parameters.AddWithValue("@Prefix", prefix);
    cmd.CommandText = query;
    return PopulateAutoComplete(cmd);
}

[WebMethod]
public static string[] GetStates(string prefix, int parentId)
{
    SqlCommand cmd = new SqlCommand();
    string query = "SELECT StateId, StateName FROM States WHERE StateName LIKE + '%' + @Prefix + '%' AND CountryId=@CountryId";
    cmd.Parameters.AddWithValue("@Prefix", prefix);
    cmd.Parameters.AddWithValue("@CountryId", parentId);
    cmd.CommandText = query;
    return PopulateAutoComplete(cmd);
}

[WebMethod]
public static string[] GetCities(string prefix, int parentId)
{
    SqlCommand cmd = new SqlCommand();
    string query = "SELECT CityId, CityName FROM Cities WHERE CityName LIKE + '%' + @Prefix + '%' AND StateId=@StateId";
    cmd.Parameters.AddWithValue("@Prefix", prefix);
    cmd.Parameters.AddWithValue("@StateId", parentId); cmd.CommandText = query;
    return PopulateAutoComplete(cmd);
}

private static string[] PopulateAutoComplete(SqlCommand cmd)
{
    List<string> autocompleteItems = new List<string>();
    using (SqlConnection conn = new SqlConnection())
    {
        conn.ConnectionString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        cmd.Connection = conn;
        conn.Open();
        using (SqlDataReader sdr = cmd.ExecuteReader())
        {
            while (sdr.Read())
            {
                autocompleteItems.Add(string.Format("{0}-{1}", sdr[1], sdr[0]));
            }
        }
        conn.Close();
    }
    return autocompleteItems.ToArray();
}

protected void Submit(object sender, EventArgs e)
{
    string countryName = Request.Form[txtCountry.UniqueID];
    string countryId = Request.Form[hfCountry.UniqueID];

    string stateName = Request.Form[txtState.UniqueID];
    string stateId = Request.Form[hfState.UniqueID];

    string cityName = Request.Form[txtCity.UniqueID];
    string cityId = Request.Form[hfCity.UniqueID];

    string message = string.Format("Country: {0} {1}\\n", countryName, countryId);
    message += string.Format("State: {0} {1}\\n", stateName, stateId);
    message += string.Format("City: {0} {1}", cityName, cityId);
    ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('" + message + "');", true);
}

VB.Net

<WebMethod()> _
Public Shared Function GetCountries(prefix As String, parentId As Integer) As String()
    Dim cmd As New SqlCommand()
    Dim query As String = "SELECT CountryId, CountryName FROM Countries WHERE CountryName LIKE + '%' + @Prefix + '%'"
    cmd.Parameters.AddWithValue("@Prefix", prefix)
    cmd.CommandText = query
    Return PopulateAutoComplete(cmd)
End Function

<WebMethod()> _
Public Shared Function GetStates(prefix As String, parentId As Integer) As String()
    Dim cmd As New SqlCommand()
    Dim query As String = "SELECT StateId, StateName FROM States WHERE StateName LIKE + '%' + @Prefix + '%' AND CountryId=@CountryId"
    cmd.Parameters.AddWithValue("@Prefix", prefix)
    cmd.Parameters.AddWithValue("@CountryId", parentId)
    cmd.CommandText = query
    Return PopulateAutoComplete(cmd)
End Function

<WebMethod()> _
Public Shared Function GetCities(prefix As String, parentId As Integer) As String()
    Dim cmd As New SqlCommand()
    Dim query As String = "SELECT CityId, CityName FROM Cities WHERE CityName LIKE + '%' + @Prefix + '%' AND StateId=@StateId"
    cmd.Parameters.AddWithValue("@Prefix", prefix)
    cmd.Parameters.AddWithValue("@StateId", parentId)
    cmd.CommandText = query
    Return PopulateAutoComplete(cmd)
End Function

Private Shared Function PopulateAutoComplete(cmd As SqlCommand) As String()
    Dim autocompleteItems As New List(Of String)()
    Using conn As New SqlConnection()
        conn.ConnectionString = ConfigurationManager.ConnectionStrings("constr").ConnectionString
        cmd.Connection = conn
        conn.Open()
        Using sdr As SqlDataReader = cmd.ExecuteReader()
            While sdr.Read()
                autocompleteItems.Add(String.Format("{0}-{1}", sdr(1), sdr(0)))
            End While
        End Using
        conn.Close()
    End Using
    Return autocompleteItems.ToArray()
End Function

Protected Sub Submit(sender As Object, e As EventArgs)
    Dim countryName As String = Request.Form(txtCountry.UniqueID)
    Dim countryId As String = Request.Form(hfCountry.UniqueID)

    Dim stateName As String = Request.Form(txtState.UniqueID)
    Dim stateId As String = Request.Form(hfState.UniqueID)

    Dim cityName As String = Request.Form(txtCity.UniqueID)
    Dim cityId As String = Request.Form(hfCity.UniqueID)

    Dim message As String = String.Format("Country: {0} {1}\n", countryName, countryId)
    message += String.Format("State: {0} {1}\n", stateName, stateId)
    message += String.Format("City: {0} {1}", cityName, cityId)
    ClientScript.RegisterStartupScript(Me.GetType(), "alert", "alert('" & message + "');", True)
End Sub

Screenshot