两个DropDownList数据绑定联动(数据库)

设计如图:

打开源:

<body>
    <form id="form1" runat="server">
    <div>
   
        省份：<asp:DropDownList ID="ddlProvince" runat="server"
            onselectedindexchanged="ddlProvince_SelectedIndexChanged" AutoPostBack="true">
        </asp:DropDownList>
      
        城市： <asp:DropDownList ID="ddlCity" runat="server">
        </asp:DropDownList>
   
    </div>
    </form>
</body>

 

建立数据库访问DBHelper类GetDataTable方法

    public static DataTable GetDataTable(string sql)
    {
        SqlConnection conn = new SqlConnection("server=.;database=Provinces;uid=sa;pwd=sa2005");
        conn.Open();
        SqlCommand cmd = new SqlCommand(sql, conn);
        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
        DataTable dt = new DataTable();
        dt.Load(dr);
        dr.Close();
        return dt;
    }

 

DropDownList后置cs文件:

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            BingdingDDLProvince();
            BingdingDDLCity();

        }
    }

    /// <summary>
    /// 绑定省份
    /// </summary>
    protected void BingdingDDLProvince()
    {
        string sql = "select * from province";
        this.ddlProvince.DataSource = DBHelper.GetDataTable(sql);
        this.ddlProvince.DataTextField = "ProName";
        this.ddlProvince.DataValueField = "ProId";
        this.ddlProvince.DataBind();
    }

    protected void BingdingDDLCity()
    {
        string sql = "select cityName from city where cityId='"+ this.ddlProvince.SelectedValue +"'";
        this.ddlCity.DataSource = DBHelper.GetDataTable(sql);
        this.ddlCity.DataTextField = "cityName";
        this.ddlCity.DataBind();
    }

　//双击省份DropDownList控件

    protected void ddlProvince_SelectedIndexChanged(object sender, EventArgs e)
    {
        string id = this.ddlProvince.SelectedValue;
        string sql = "select * from city where cityId="+id;
        Response.Write(sql);
        this.ddlCity.DataSource = DBHelper.GetDataTable(sql);
        this.ddlCity.DataTextField = "cityName";
        this.ddlCity.DataBind();
    }
}

 运行结果:

 

 

 

posted @ 2009-12-29 14:04  ^特殊П佀命^  阅读(2311)  评论(0)    收藏  举报