public partial class _Default : System.Web.UI.Page
{
protected string title=" Hello, everyone "; // The front desk code <title><%#title %></title>
protected void Page_Load(object sender, EventArgs e)
{
DataSet ds = new DataSet();
string sql = ConfigurationManager.ConnectionStrings["strsql"].ConnectionString;
using (SqlConnection sqlCnn=new SqlConnection(sql))
{
using (SqlCommand sqlCmm=sqlCnn.CreateCommand())
{
sqlCmm.CommandText = "select * from List";
SqlDataAdapter adapter = new SqlDataAdapter(sqlCmm);
adapter.Fill(ds);
}
this.RadioButtonList1.DataSource = ds.Tables[0];
this.RadioButtonList1.DataTextField = "listname";
this.RadioButtonList1.DataValueField = "id";
//this.RadioButtonList1.DataBind();
this.CheckBoxList1.DataSource = ds.Tables[0];
this.CheckBoxList1.DataTextField = "listname";
this.CheckBoxList1.DataValueField = "id";
//this.RadioButtonList1.DataBind();
this.DataBind();
} // Data binding to RadioButtonList,CheckBoxList
if (!IsPostBack)
{
DataSet ds1 = new DataSet();
using (SqlConnection sqlCnn1 = new SqlConnection(sql))
{
using (SqlCommand sqlCmm1 = sqlCnn1.CreateCommand())
{
sqlCmm1.CommandText = "select provinceid,provincename from Province";
SqlDataAdapter adapter = new SqlDataAdapter(sqlCmm1);
adapter.Fill(ds1);
this.DropDownList1.DataSource = ds1.Tables[0];
this.DropDownList1.DataTextField = "provincename";
this.DropDownList1.DataValueField = "provinceid";
this.DropDownList1.DataBind();
}
}
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
DataSet ds = new DataSet();
string str = ConfigurationManager.ConnectionStrings["strsql"].ConnectionString;
using (SqlConnection sqlCnn = new SqlConnection(str))
{
using (SqlCommand sqlCmm = sqlCnn.CreateCommand())
{
sqlCmm.CommandText = "select cityid,cityname from City where provinceid='" + this.DropDownList1.SelectedValue + "'";
SqlDataAdapter adapter = new SqlDataAdapter(sqlCmm);
adapter.Fill(ds);
this.DropDownList2.DataSource = ds.Tables[0];
this.DropDownList2.DataTextField = "cityname";
this.DropDownList2.DataValueField = "cityid";
this.DropDownList2.DataBind();
}
}
}// Implement provinces and cities 2 Levels of linkage
}