Ajax实现无刷新三联动下拉框_[Asp.Net教程]                                           					

1.html代码
    
        Ajax实现无刷新三联动下拉框
        
        
        
        
        
    
    
        
    
2.cs代码
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace AjaxTest
{
    /**//// 
    /// Summary description for WebForm1.
    /// 
    public class WebForm1 : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.DropDownList DropDownList1;
        protected System.Web.UI.WebControls.DropDownList DropDownList2;
        protected System.Web.UI.WebControls.TextBox TextBox1;
        protected System.Web.UI.WebControls.DropDownList DropDownList3;
    
        private void Page_Load(object sender, System.EventArgs e)
        {    
            Ajax.Utility.RegisterTypeForAjax(typeof(AjaxMethod));
            if(!Page.IsPostBack)
            {
                this.DropDownList1.DataSource=AjaxMethod.GetProvinceList();
                this.DropDownList1.DataTextField="province";
                this.DropDownList1.DataValueField="provinceID";
                this.DropDownList1.DataBind();
                
                this.DropDownList1.Attributes.Add("onclick","cityResult();");
                this.DropDownList2.Attributes.Add("onclick","areaResult();");
            }
        }
        Web Form Designer generated code#region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// 
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// 
        private void InitializeComponent()
        {    
            this.Load += new System.EventHandler(this.Page_Load);
        }
        #endregion        
    }
}
3.AjaxMethod
using System;
using System.Data;
using System.Data.SqlClient;
namespace AjaxTest
{
    /**//// 
    /// Summary description for AjaxMethod.
    /// 
    public class AjaxMethod
    {
        GetProvinceList#region GetProvinceList
        public static DataSet GetProvinceList()
        {
            string sql="select * from province";
            return GetDataSet(sql);
        }
        #endregion
        GetCityList#region GetCityList
        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
        public  DataSet GetCityList(int provinceid)
        {
            string sql="select * from city where father="+provinceid;
            return GetDataSet(sql);            
        }
        #endregion
        GetAreaList#region GetAreaList
        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
        public  DataSet GetAreaList(int cityid)
        {
            string sql="select * from area where father="+cityid;
            return GetDataSet(sql);            
        }
        #endregion
    
        GetDataSet#region GetDataSet
        public static DataSet GetDataSet(string sql)
        {
            string ConnectionString=System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"];
            SqlDataAdapter    sda =new SqlDataAdapter(sql,ConnectionString);
            DataSet ds=new DataSet();
            sda.Fill(ds);
            return ds;
        }
        #endregion
    }
}
4.web.config
            
    
5.ajax.dll下载/Files/singlepine/Ajax.rar
6.真实数据库下载area1.rar
7.源代码下载AjaxTest.rar 
来源:cnblogs