Ajax implementation of no refresh provinces, cities and counties three-level linkage _ajax related

The example of this article for everyone to share the AJAX implementation of no refresh provinces and cities three-level linkage of the specific code for your reference, the specific content as follows

Effect Chart:

Implementation code:

1, HTML:

2, Webservice1.asmx

Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Web;


Using System.Web.Services; Namespace city and county level three linkage {///<summary>///WebService1 Summary description///</summary> [WebService (Namespace = "http:/ /tempuri.org/")] [webservicebinding (ConformsTo = wsiprofiles.basicprofile1_1)] [System.ComponentModel.ToolboxItem (
   FALSE)]//To allow the use of ASP.net AJAX to invoke this Web service from a script, uncomment the downlink. [System.Web.Script.Services.ScriptService] public class WebService1:System.Web.Services.WebService {[Webmetho
    D] public string HelloWorld () {return ' Hello world ';
      [WebMethod] public list<model.province> getprovince () {bll.province Bpro = new Bll.province (); list<model.province> list = Bpro.
      Getlistmodel ();
    return list; [WebMethod] public list<model.city> Getcitybypro (string proid) {bll.city bcity = new Bll.city ()
      ; list<model.city> list = bcity. Getlistmodel ("FatHer= ' "+ proid +" "");
    return list; [WebMethod] public list<model.area> getareabycity (string cityid) {Bll.area Barea = new Bll.area
      (); list<model.area> list = Barea.
      Getlistmodel ("father= '" + Cityid + "");
    return list;
 }
  }
}

Add the following properties to the City.cs and Area.cs in the three-layer BLL layer

City.cs: Public
  list<model.city> Getlistmodel (string strSQL)
    {return
      dal. Getlistmodel (strSQL);
    }
Area.cs: Public
   list<model.area> Getlistmodel (string strSQL)
    {return
      dal. Getlistmodel (strSQL);
    }

Add the following methods to the City.cs and Area.cs in the three-layer dal layer, respectively

City.cs:public system.collections.generic.list<model.city> Getlistmodel (string strsql) {System.collec tions.
      generic.list<model.city> List = new system.collections.generic.list<model.city> (); DataTable dt = GetList (strSQL).
      Tables[0]; foreach (DataRow row in dt.
        Rows) {model.city mcity = new model.city ();
        Mcity.id = Convert.ToInt32 (row["id")); Mcity.cityid = row["Cityid"].
        ToString (); Mcity.cityname = row["CityName"].
        ToString (); List.
      ADD (mcity);
    } return list; }//area.cs:public system.collections.generic.list<model.area> Getlistmodel (string strsql) {DataTable DT = GetList (strSQL).
      Tables[0];
      system.collections.generic.list<model.area> List = new system.collections.generic.list<model.area> (); foreach (DataRow row in dt. Rows) {Model.area Marea = new Model.area () {id = Convert.ToInt32 (row["id"]), a ReaID = row["Areaid"]. ToString (), areaname = row["AreaName"].
        ToString ()}; List.
      ADD (Marea);
    } return list; }

The above is the entire content of this article, I hope to help you learn.