dropdowntest.aspx.cs

啊师傅大幅电饭锅功夫功夫那个复合共和国和电饭锅辅导和的复合费功夫的功夫的是个

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
public partial class dropDownTest : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            SqlConnection con = DB.createConnection();
            con.Open();
            SqlCommand cmdProvince = new SqlCommand("select * from province",con);
            SqlDataReader sdr = cmdProvince.ExecuteReader();
            this.ddlProvince.DataSource = sdr;
            this.ddlProvince.DataTextField = "proName";
            this.ddlProvince.DataValueField = "proID";
            this.ddlProvince.DataBind();
            sdr.Close();
            SqlCommand cmdCity = new SqlCommand("select * from city where proID="+this.ddlProvince.SelectedValue,con);
            SqlDataReader sdr1 = cmdCity.ExecuteReader();
            this.ddlCity.DataSource = sdr1;
            this.ddlCity.DataTextField = "cityName";
            this.ddlCity.DataValueField = "cityID";
            this.ddlCity.DataBind();
            sdr1.Close();
            con.Close();
        
        
        }
    }
    protected void ddlProvince_SelectedIndexChanged(object sender, EventArgs e)
    {

        SqlConnection con = DB.createConnection();
        con.Open();
        SqlCommand cmdCity = new SqlCommand("select * from city where proID=" + this.ddlProvince.SelectedValue, con);
        SqlDataReader sdr1 = cmdCity.ExecuteReader();
        this.ddlCity.DataSource = sdr1;
        this.ddlCity.DataTextField = "cityName";
        this.ddlCity.DataValueField = "cityID";
        this.ddlCity.DataBind();
        sdr1.Close();
        con.Close();
    }
}