City, State and Country usingcascading dropdownlist(through Webservice)

ASP.Net Page:

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %>

Country:

<asp:DropDownList ID="ddlCountry" CssClass="ddlist" Width="202" runat="server">

</asp:DropDownList>

<asp:CascadingDropDown ID="CountryCascading" runat="server" Category="Country"  TargetControlID="ddlCountry"

PromptText="Select Country" ServiceMethod="BindCountrydropdown" LoadingText="Loading Countries..."

ServicePath="~/Assets/DropdownWebService.asmx">

</asp:CascadingDropDown>

State:

<asp:DropDownList ID="ddlState" CssClass="ddlist" Width="202" runat="server">

</asp:DropDownList>

<asp:CascadingDropDown ID="StateCascading" runat="server" Category="State" TargetControlID="ddlState"

ParentControlID="ddlCountry" LoadingText="Loading States..." PromptText="Select State"

ServiceMethod="BindStatedropdown" ServicePath="~/Assets/DropdownWebService.asmx">

</asp:CascadingDropDown>

City:

<asp:DropDownList ID="ddlCity" CssClass="ddlist" Width="202" runat="server">

</asp:DropDownList>

<asp:CascadingDropDown ID="RegionCascading" runat="server" Category="Region" TargetControlID="ddlCity"

ParentControlID="ddlState" LoadingText="Loading Cities..." PromptText="Select City"

ServiceMethod="BindRegiondropdown" ServicePath="~/Assets/DropdownWebService.asmx">

</asp:CascadingDropDown>

.CS File

if(Convert.ToInt32(objCompanyDT.Rows[0]["CountryID"])!=0)

{

  CountryCascading.SelectedValue = objCompanyDT.Rows[0]["CountryID"].ToString();

}

if (ddlCountry.SelectedItem.Text != "Select Country" && ddlCountry.SelectedItem.Text != "")

{

  objCompany.Country = ddlCountry.SelectedItem.Value;

}

In Web Service File:

using System;

using System.Collections;

using System.Web;

using System.Web.Services;

using System.Web.Services.Protocols;

using System.Data.SqlClient;

using System.Collections.Generic;

using System.Collections.Specialized;

using AjaxControlToolkit;

using System.Configuration;

using System.Data;

using IUSCRMLib.DataManagers;

namespace IUSCRM.Assets

{

[WebService(Namespace = "http://tempuri.org/")]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

[System.ComponentModel.ToolboxItem(false)]

[System.Web.Script.Services.ScriptService()]

public class DropdownWebService : System.Web.Services.WebService

{

[WebMethod]

public CascadingDropDownNameValue[] BindCountrydropdown(string knownCategoryValues, string category)

{

  SqlConnection concountry = IUSCRMLib.SqlHelper.GetDBConnetion();

  SqlCommand cmdcountry = new SqlCommand("select * from Countries where IsActive=1",  concountry);

  SqlDataAdapter dacountry = new SqlDataAdapter(cmdcountry);

  cmdcountry.ExecuteNonQuery();

  DataSet dscountry = new DataSet();

  dacountry.Fill(dscountry);

  List<CascadingDropDownNameValue> countrydetails = new List<CascadingDropDownNameValue>();

  foreach (DataRow dtrow in dscountry.Tables[0].Rows)

  {

    string CountryID = dtrow["CountryId"].ToString();

    string CountryName = dtrow["Country"].ToString();

    countrydetails.Add(new CascadingDropDownNameValue(CountryName, CountryID));

  }

  return countrydetails.ToArray();

 }

[WebMethod]

public CascadingDropDownNameValue[] BindStatedropdown(string knownCategoryValues, string category)

{

  int CountryID;

  StringDictionary countrydetails =  AjaxControlToolkit.CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues);

  CountryID = Convert.ToInt32(countrydetails["Country"]);

  SqlConnection constate = IUSCRMLib.SqlHelper.GetDBConnetion();

  SqlCommand cmdstate = new SqlCommand("select * from State where CountryID=@CountryID and  State <> (select Country from Countries where CountryId=@CountryID) and IsActive=1", constate);

  cmdstate.Parameters.AddWithValue("@CountryID", CountryID);

  cmdstate.ExecuteNonQuery();

  SqlDataAdapter dastate = new SqlDataAdapter(cmdstate);

  DataSet dsstate = new DataSet();

  dastate.Fill(dsstate);

  List<CascadingDropDownNameValue> statedetails = new List<CascadingDropDownNameValue>();

  foreach (DataRow dtstaterow in dsstate.Tables[0].Rows)

  {

     string stateID = dtstaterow["StateID"].ToString();

     string statename = dtstaterow["State"].ToString();

     statedetails.Add(new CascadingDropDownNameValue(statename, stateID));

  }

  return statedetails.ToArray();

}

[WebMethod]

public CascadingDropDownNameValue[] BindRegiondropdown(string knownCategoryValues, string category)

{

  int stateID;

  StringDictionary statedetails = AjaxControlToolkit.CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues);

  stateID = Convert.ToInt32(statedetails["State"]);

  SqlConnection conregion = IUSCRMLib.SqlHelper.GetDBConnetion();

  SqlCommand cmdregion = new SqlCommand("Select * from Cities where StateID=@StateID and City <> (select state from state where StateID=@StateID) and IsActive=1 ", conregion);

  cmdregion.Parameters.AddWithValue("@StateID", stateID);

  cmdregion.ExecuteNonQuery();

  SqlDataAdapter daregion = new SqlDataAdapter(cmdregion);

  DataSet dsregion = new DataSet();

  daregion.Fill(dsregion);

  List<CascadingDropDownNameValue> regiondetails = new List<CascadingDropDownNameValue>();

  foreach (DataRow dtregionrow in dsregion.Tables[0].Rows)

  {

     string regionID = dtregionrow["CityId"].ToString();

     string regionname = dtregionrow["City"].ToString();

     regiondetails.Add(new CascadingDropDownNameValue(regionname, regionID));

  }

  return regiondetails.ToArray();

}

}

}