省市县三级联动（二）

这种方法是从一张省市表中获得相应的数据

1.首先在数据库创建一张 T_Arear表，并插入相应的内容

CREATE TABLE T_Arear

(

Id INT IDENTITY PRIMARY KEY,

A_Id VARCHAR(8),

A_Name VARCHAR(16),

A_ParentId VARCHAR(8)

)

--添加省级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('P001','河北省','0');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('P002','河南省','0');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('P003','山东省','0');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('P004','山西省','0');

--添加河北省市级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C001','石家庄','P001');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C002','保定','P001');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C003','邯郸','P001');

--添加河南省市级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C004','郑州','P002');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C005','洛阳','P002');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C006','商丘','P002');

--添加山西省市级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C007','太原','P003');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C008','运城','P003');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C009','大同','P003');

--添加山东省市级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C010','济南','P004');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C011','青岛','P004');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('C012','淄博','P004');

--添加河北省石家庄区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A001','长安区','C001');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A002','桥东区','C001');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A003','桥西区','C001');

--添加河北省保定区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A004','满城','C002');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A005','徐水','C002');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A006','阜平','C002');

-添加河北省邯郸区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A007','临漳','C003');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A008','成安','C003');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A009','大名','C003');

--添加河南省郑州区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A009','金水','C004');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A010','惠济','C004');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A012','经开区','C004');

--添加河南省洛阳区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A013','新安','C005');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A014','嵩县','C005');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A015','宜阳','C005');

-添加河南省商丘区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A016','梁园','C006');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A017','永城','C006');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A018','宁陵','C006');

--添加山西省太原区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A019','小店','C007');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A020','迎泽','C007');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A021','阳曲','C007');

--添加山西省运城区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A022','盐湖','C008');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A023','万荣','C008');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A024','闻喜','C008');

--添加山西省大同市区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A025','新荣','C009');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A026','阳高','C009');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A027','天镇','C009');

--添加山东省济南区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A028','历下','C010');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A029','天桥','C010');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A030','长清','C010');

--添加山东省青岛区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A031','崂山','C011');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A032','黄岛','C011');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A033','胶州','C011');

--添加山东淄博区县级数据

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A034','张店','C012');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A035','博山','C012');

INSERT INTO T_Arear(A_Id,A_Name,A_ParentId) VALUES('A036','桓台','C012');

二、

1、---这是省市选择器的前台界面


2、这是后台代码

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data.SqlClient;

using System.Data;

namespace 新闻管理系统

{

public partial class 省市选择器yhb : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

GetProvince();

}

}

private DataTable LoadData(string id)

{

string constr = "data source=LOVE-PC\\SQLEXPRESSPC;initial catalog=News;user id=sa;password=admin";

using (SqlConnection conn = new SqlConnection(constr))

{

conn.Open();

using (SqlCommand cmd = conn.CreateCommand())

{

cmd.CommandText = "SELECT A_Id,A_Name FROM T_Arear WHERE A_ParentId=@parentid ORDER BY A_Id";

cmd.Parameters.AddWithValue("@parentid", id);

SqlDataAdapter adapter = new SqlDataAdapter(cmd);

DataTable dt = new DataTable();

adapter.Fill(dt);

cmd.Dispose();

conn.Dispose();

return dt;

}

}

}

private void GetProvince()

{

DataTable dt = LoadData("0");

this.ddlProvince.DataSource = dt;

//指定下拉列表括要显示的字段的值

this.ddlProvince.DataTextField = "A_Name";

//指定下拉列表括的value属性要绑定的字段的值

this.ddlProvince.DataValueField = "A_Id";

this.ddlProvince.DataBind();

//插入默认选中项

ListItem item = new ListItem("--------请选择--------","0");

this.ddlProvince.Items.Insert(0,item);

}

protected void ddlProvince_SelectedIndexChanged(object sender, EventArgs e)

{

string id = this.ddlProvince.SelectedItem.Value;

if(id!="0")

{

DataTable dt = LoadData(id);

this.ddlCity.DataSource = dt;

this.ddlCity.DataTextField = "A_Name";

this.ddlCity.DataValueField = "A_Id";

this.ddlCity.DataBind();

string selectid = this.ddlCity.SelectedItem.Value;

DataTable dt1 = LoadData(selectid);

this.ddlArear.DataSource = dt1;

this.ddlArear.DataTextField = "A_Name";

this.ddlArear.DataValueField = "A_Id";

this.ddlArear.DataBind();

}

else

{

ddlCity.Items.Clear();

ddlArear.Items.Clear();

}

}

protected void ddlCity_SelectedIndexChanged(object sender, EventArgs e)

{

string cityid = this.ddlCity.SelectedItem.Value;

DataTable dt = LoadData(cityid); ;

this.ddlArear.DataSource = dt;

this.ddlArear.DataTextField = "A_Name";

this.ddlArear.DataValueField = "A_Id";

this.ddlArear.DataBind();

}

}

}