how to deal with SelectedIndexChange of dropdownlist in Usercontrol Added dynamicaly

Question

hello everyone I have three DropDown list of CountryStateCity in a User Control. I have populated the country DropDownList on page load of .ascx page ie. on UserControl. Now i want to populate the state ddl on selectedindexchange event of Countryddl bt finding difficulty to add that event on parent page. plz can anyone help me to sortout this problem.

Tushar Malhotra · Answer

the asp code for the country ddl. onselectedindexchanged=country_SelectedIndexChanged1 ontextchanged=country_TextChanged Width=176px> One of the property of ddl is AutoPostBack which is to be set true... this allows to load the next ddl on its selection. Now the SelectedIndexChanged event of the country ddl protected void country_SelectedIndexChanged1(object sender EventArgs e) { int ch = (int)country.SelectedIndex; switch (ch) { case 0: state.Items.Clear(); state.Items.Add(Delhi); state.Items.Add(Punjab); state.Items.Add(U.P.); state.Items.Add(Maharashtra); break; case 1: state.Items.Clear(); state.Items.Add(Islamabad); state.Items.Add(Punjab); state.Items.Add(Karachi); state.Items.Add(Lahor); break; default: Label1.Text = Select a country first; break; } } The switch-case will check the index of the country ddl n will load the states. If u r loading the ddls from a database then u have to fire a query as select state from country where country ' + country.Text + '; and then u will get a data set taht u can bound to state ddl...

Anusha Srivastava · Answer

I have done this coding on the User Control. 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; public partial class userControll_AddressUC : System.Web.UI. UserControl { /// /// Method for Page_Load /// /// /// /// #region Page_Load protected void Page_Load( object sender EventArgs e) { try { if (!IsPostBack) { CountoryMaster oCountoryMaster = new CountoryMaster (); CountryDB oCountryDB = new CountryDB (); DataTable dtBindListCountry = oCountryDB.GetCountryName(oCountoryMaster); if (dtBindListCountry.Rows.Count > 0) { ddlAddCountry.DataSource = dtBindListCountry; ddlAddCountry.DataTextField = dtBindListCountry.Columns[ country_name ].ToString(); ddlAddCountry.DataValueField = dtBindListCountry.Columns[ country_id ].ToString(); ddlAddCountry.DataBind(); } dtBindListCountry.Dispose(); } } catch ( Exception ex) { throw ex; } } #endregion /// /// Method for ddlAddState_SelectedIndexChanged /// /// /// /// #region BindCity protected void BindCity( object sender EventArgs e) { try { CityMaster oCityMaster = new CityMaster (); CityDB oCityDB = new CityDB (); oCityMaster.StateId = ddlAddState.SelectedValue; oCityMaster.CountryId = Convert .ToInt32(ddlAddCountry.SelectedValue); DataTable dtCity = oCityDB.getSelectCityByStateId(oCityMaster); if (dtCity.Rows.Count > 0) { ddlAddCity.DataSource = dtCity; ddlAddCity.DataTextField = dtCity.Columns[ city_name ].ToString(); ddlAddCity.DataValueField = dtCity.Columns[ city_id ].ToString(); ddlAddCity.DataBind(); } ddlAddCity.Items.Insert(0 new ListItem ( Please Select...  -1  true )); dtCity.Dispose(); } catch ( Exception ex) { throw ex; } } #endregion /// /// Method for ddlAddCountry_SelectedIndexChanged /// /// /// /// #region BindState protected void BindState( object sender EventArgs e) { try { State oState = new State (); StateDb oStateDb = new StateDb (); oState.CountryId = Convert .ToInt32(ddlAddCountry.SelectedValue); DataTable dtState = oStateDb.getStateByCountry(oState); if (dtState.Rows.Count > 0) { ddlAddState.DataSource = dtState; ddlAddState.DataTextField = dtState.Columns[ state_name ].ToString(); ddlAddState.DataValueField = dtState.Columns[ state_id ].ToString(); ddlAddState.DataBind(); } ddlAddState.Items.Insert(0 new ListItem ( Please Select...  -1  true )); dtState.Dispose(); } catch ( Exception ex) { throw ex; } } #endregion asp : UpdatePanel ID =UpnlAddDetails runat =server UpdateMode =Conditional> ContentTemplate > table border =0 cellpadding =1 cellspacing =3 width =100%> tr > td align =left width =35%> Country td > td align =left width =65%> asp : DropDownList ID =ddlAddCountry runat =server AutoPostBack =true CssClass =fields OnSelectedIndexChanged =BindState> asp : DropDownList > td > tr > tr > td align =left width =35%> State td > td align =left width =65%> asp : DropDownList ID =ddlAddState runat =server CssClass =fields AutoPostBack =true OnSelectedIndexChanged =BindCity> asp : DropDownList > td > tr > tr > td align =left width =35%> td > td align =left valign =middle width =65%> Other : asp : TextBox ID =txtOtherState runat =server CssClass =INPUT-BOX> asp : TextBox > td > tr > tr > td align =left width =35%> City td > td align =left width =65%> asp : DropDownList ID =ddlAddCity runat =server CssClass =fields> asp : DropDownList > td > tr > tr > td align =left width =35%> td > td align =left width =65%> Other : asp : TextBox ID =txtOtherCity runat =server CssClass =INPUT-BOX> asp : TextBox > td > tr > table > ContentTemplate > Triggers > asp : AsyncPostBackTrigger ControlID =ddlAddCountry EventName =SelectedIndexChanged /> asp : AsyncPostBackTrigger ControlID =ddlAddState EventName =SelectedIndexChanged /> Triggers > asp : UpdatePanel > And the Followingn on the parent page asp : DropDownList ID =ddlAddressType runat =server AutoPostBack =true CssClass =fields OnSelectedIndexChanged =ddlAddressType_SelectedIndexChanged> asp : ListItem Text =...Select... Value = Selected =True> asp : ListItem > asp : ListItem Text =Home Value =Home> asp : ListItem > asp : ListItem Text =Business Value =Business> asp : ListItem > asp : DropDownList > if (ddlAddressType.SelectedValue == Home ) { Control AddressHome = LoadControl( ~/userControll/AddressUC.ascx ); pnlUCPermanent.Visible = true ; pnlUCPermanent.Controls.Add(AddressHome); pnlUCBussisns.Visible = false ; } if (ddlAddressType.SelectedValue == Home ) { Control AddressBuss = LoadControl( ~/userControll/AddressUC.ascx ); pnlUCBussisns.Visible = true ; pnlUCBussisns.Controls.Add(AddressBuss); pnlUCPermanent.Visible = true ; } But the selected index change for the country ddl is not fired.

Tushar Malhotra · Answer

use switch-case in the country drop down list's SelectedIndexChanged event n maps its SelectedIndex property. On Case 0 write the code to add the items in the state ddl int indx = (int)country.SelectedIndex; switch(indx) { case 0://let the countrty be India state.Items.Add(Maharashtra); // and so on.... } similarly do for the city ddl