How to select city from its state and state from its country using asp.net?

Question

How to select city from its state and state from its country using asp.net?If I used three dropdownlist One for state next one for city and last one for country.Then if I select country then according to that the state is displayed in next dropdownlist and when selecting the state the corrosponding city is displayed or come to the dropdownlist?give me an example also?

WH Xu · Answer

Hi, Richa Garg : It 's 3 level cascade combo box question: Here is a Javascript example,hope it can help you. var arrText = new Array(5); var arrValue = new Array(arrText.length); function objSetOption(select1, select2, select3) { this.select1 = select1; this.select2 = select2; this.select3 = select3; } arrText[0]= new objSetOption("item1:", "item2_1:,item2_2:", "item3_1:,item3_2:"); arrText[1] = new objSetOption("Object0:1", "Object1:1,Object2:2,Object3:3", "Object4:2,Object5:3"); arrText[2] = new objSetOption("??:2", "??b2_1:?b2_1,??b2_2:?b2_2", "??b3_1:?b3_1,??b3_2:?b3_2"); arrText[3] = new objSetOption("??c:?c", "??c2_1:?c2_1,??c2_2:?c2_2", "??c3_1:?c3_1,??c3_2:?c3_2"); arrText[4] = new objSetOption("??d:?d", "??d2_1:?d2_1,??d2_2:?d2_2", "??d3_1:?d3_1,??d3_2:?d3_2"); arrText[5] = new objSetOption("??e:?e", "??e2_1:?e2_1,??e2_2:?e2_2", "??e3_1:?e3_1,??e3_2:?e3_2"); function select(sValue1, sValue2, sValue3) { var eltSelect1 = document.myform.classid; var eltSelect2 = document.myform.suid; var eltSelect3 = document.myform.gid; var arrSelect1, arrSelect2, arrSelect3; var arrData1, arrData2, arrData3; with(eltSelect1) { var strSelect = options[selectedIndex].value; } for(i = 0;i arrSelect1 = arrText[i].select1; arrData1 = arrSelect1.split(":"); if (arrData1[1] == strSelect) { arrSelect2 = (arrText[i].select2).split(","); for(j = 0;j arrData2 = arrSelect2[j].split(":"); with(eltSelect2) { length = arrSelect2.length; options[j].text = arrData2[0]; options[j].value = arrData2[1]; if (arrData2[1] == sValue2) { options[j].selected = true; } } } arrSelect3 = (arrText[i].select3).split(","); for(j = 0;j arrData3 = arrSelect3[j].split(":"); with(eltSelect3) { length = arrSelect3.length; options[j].text = arrData3[0]; options[j].value = arrData3[1]; if (arrData3[1] == sValue3) { options[j].selected = true; } } } break; } } } function init(sValue1, sValue2, sValue3) { var eltSelect1 = document.myform.classid; var eltSelect2 = document.myform.suid; var eltSelect3 = document.myform.gid; var arrSelect1, arrSelect2, arrSelect3; var arrData1, arrData2, arrData3; if (eltSelect1 != undefined && eltSelect2 != undefined && eltSelect3 != undefined) { with(eltSelect2) { arrSelect2 = (arrText[0].select2).split(","); length = arrSelect2.length; for(i = 0;i arrData2 = arrSelect2[i].split(":"); options[i].text = arrData2[0]; options[i].value = arrData2[1]; } } with(eltSelect3) { arrSelect3 = (arrText[0].select3).split(","); length = arrSelect3.length; for(i = 0;i arrData3 = arrSelect3[i].split(":"); options[i].text = arrData3[0]; options[i].value = arrData3[1]; } } with(eltSelect1) { length = arrText.length; for(i = 0;i arrSelect1 = arrText[i].select1; arrData1 = arrSelect1.split(":"); options[i].text = arrData1[0]; options[i].value = arrData1[1]; if (arrData1[1] == sValue1) { options[i].selected = true; select("", sValue2, sValue3); } } } } } //init(); //????? init("2", "?b2_1", "?b3_2"); //???????? // -->

Satyapriya Nayak · Answer

Hi Richa, Try this... Untitled Page ForeColor="Red" Width="100px"> AppendDataBoundItems="true" runat="server" Height="20px" Width="156px" onselectedindexchanged="ddlcountry_SelectedIndexChanged" Font-Bold="True" ForeColor="#FF9900"> ForeColor="Red" Width="100px"> AppendDataBoundItems ="true" runat="server" Height="20px" Width="155px" onselectedindexchanged="ddlstate_SelectedIndexChanged" Font-Bold="True" ForeColor="#993300"> ForeColor="Red" Width="100px"> runat="server" Height="20px" Width="155px" Font-Bold="True" ForeColor="#CCCC00"> using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Data.SqlClient; namespace Country_state_city { public partial class _Default : System.Web.UI.Page { string strConnString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString; string str; SqlCommand com; SqlDataAdapter sqlda; DataSet ds; protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { bindcountry(); } } protected void ddlcountry_SelectedIndexChanged(object sender, EventArgs e) { bindstate(); } protected void ddlstate_SelectedIndexChanged(object sender, EventArgs e) { bindcity(); } public void bindcountry() { SqlConnection con = new SqlConnection(strConnString); con.Open(); str = "select CountryId,CountryName from Country"; com = new SqlCommand(str, con); sqlda = new SqlDataAdapter(com); ds = new DataSet(); sqlda.Fill(ds, "Country"); ddlcountry.Items.Clear(); ddlcountry.Items.Add("--Select--"); ddlcountry.DataValueField = "CountryId"; ddlcountry.DataTextField = "CountryName"; ddlcountry.DataSource = ds; ddlcountry.DataMember = "Country"; ddlcountry.DataBind(); con.Close(); } public void bindstate() { SqlConnection con = new SqlConnection(strConnString); con.Open(); str = "select StateId,StateName from State where Country_Id='" + ddlcountry.SelectedValue + "'"; com = new SqlCommand(str, con); sqlda = new SqlDataAdapter(com); ds = new DataSet(); sqlda.Fill(ds, "State"); ddlstate.Items.Clear(); ddlstate.Items.Add("--Select--"); ddlstate.DataValueField = "StateId"; ddlstate.DataTextField = "StateName"; ddlstate.DataSource = ds; ddlstate.DataMember = "State"; ddlstate.DataBind(); con.Close(); } public void bindcity() { SqlConnection con = new SqlConnection(strConnString); con.Open(); str = "select CityId,CityName from City where State_Id ='" + ddlstate.SelectedValue + "'"; com = new SqlCommand(str, con); sqlda = new SqlDataAdapter(com); ds = new DataSet(); sqlda.Fill(ds, "City"); ddlcity.Items.Clear(); ddlcity.Items.Add("--Select--"); ddlcity.DataValueField = "CityId"; ddlcity.DataTextField = "CityName"; ddlcity.DataSource = ds; ddlcity.DataMember = "City"; ddlcity.DataBind(); con.Close(); } } } Thanks If this post helps you mark it as answer