program for cascading combo box in asp.net

Question

There are two tables

in
suppose we choose one value in the combobox1 it must affect the second combobox2 for getting corresponding results related to combobox1..

ex: choose: car means it will show list of cars

choose:bike means it will show list of bike

Muralidharan Deenathayalan · Answer

Hi Vasanth, You can use Ajax control toolkit which has Ajax enabled cascading drop down. During the cascade option, it will not refresh the page,just refreshes the required control only. Try the online sample here. http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/CascadingDropDown/CascadingDropDown.aspx

Iftikar Hussain · Answer

Hi, Try like this in your aspx onselectedindexchanged="DdlVehicleType_SelectedIndexChanged" AutoPostBack="True"> Select Car Bike in your code protected void DdlVehicleType_SelectedIndexChanged(object sender, EventArgs e) { if (DdlVehicleType.SelectedValue == "") { DdlVehicle.Items.Insert(0, new ListItem("select", "0")); } else { string strConnString = @"Data Source=SQLEXPRESS;Initial Catalog=Dummy;Persist Security Info=True;User ID=MyUser;Password=Mypassword"; using (SqlConnection con = new SqlConnection(strConnString)) { string query = "select VehicleId,VehicleName from Vehicle where VehicleType='" + DdlVehicleType.SelectedValue + "'"; DataSet ds = new DataSet(); con.Open(); SqlCommand cmd = new SqlCommand(query, con); SqlDataAdapter dataAdapter = new SqlDataAdapter(cmd); dataAdapter.Fill(ds); con.Close(); DdlVehicle.DataSource = ds; DdlVehicle.DataTextField = " VehicleName "; DdlVehicle.DataValueField = " VehicleId "; DdlVehicle.DataBind(); DdlVehicle.Items.Insert(0, new ListItem("select", "0")); } } } Regards, Iftikar