联动下拉框

联动下拉框 ASP.NET实现下拉框二级联动组件 , namespace WebApplicationDlh { using System; using System.Data; using System.Drawing; using System.Web; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; using System.Data.SqlClient; using Db; ///

/// Area 的摘要说明。 ///

public class Area : System.Web.UI.UserControl { protected System.Web.UI.WebControls.DropDownList ddlProvince; protected System.Web.UI.WebControls.DropDownList ddlCity; public string strProvince { get { return ddlProvince.SelectedItem.Value; } set { ddlProvince.SelectedItem.Value = value; } } public string strCity { get { return ddlCity.SelectedItem.Value; } set { ddlCity.SelectedItem.Value = value; } } private void Page_Load(object sender, System.EventArgs e) { if(!IsPostBack) { ddlProvinceBind(); ddlCity.Items.Insert(0,"-请选择城市-"); } } private void ddlProvinceBind() { Db.Area myArea = new Db.Area(); SqlDataReader dr = myArea.GetAllProvince(); if(dr.Read()) { ddlProvince.DataSource = dr; ddlProvince.DataTextField = "Province"; ddlProvince.DataValueField = "Province"; ddlProvince.DataBind(); ddlProvince.Items.Insert(0,"-请选择省份-"); } } #region Web 窗体设计器生成的代码 override protected void OnInit(EventArgs e) { // // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。 // InitializeComponent(); base.OnInit(e); } ///

/// 设计器支持所需的方法 - 不要使用代码编辑器 /// 修改此方法的内容。 ///

private void InitializeComponent() { this.ddlProvince.SelectedIndexChanged += new System.EventHandler(this.ddlProvince_SelectedIndexChanged); , this.Load += new System.EventHandler(this.Page_Load); } #endregion private void ddlProvince_SelectedIndexChanged(object sender, System.EventArgs e) { if(ddlProvince.SelectedItem.Value == "-请选择省份-") { ddlCity.Items.Clear(); ddlCity.Items.Insert(ddlProvince.SelectedIndex,"-请选择城市-"); } else { Db.Area myArea = new Db.Area(); SqlDataReader dr = myArea.GetAllCityWhereProvince(ddlProvince.SelectedItem.Value); if(dr.Read()) { ddlCity.DataSource = dr; ddlCity.DataTextField = "City"; ddlCity.DataValueField = "ID"; ddlCity.DataBind(); } } } } } =============================================================〉 using System; using System.Data; using System.Data.SqlClient; using System.Configuration; namespace Db { ///

/// Area 的摘要说明。 ///

public class Area:Base { public Area() { // // TODO: 在此处添加构造函数逻辑 // } public SqlDataReader GetAllProvince() { strSp = "Sp_Area_SelectAll"; drSelectAll(strSp); return dr; } public SqlDataReader GetAllCityWhereProvince(string a) { conn = new SqlConnection(ConfigurationSettings.AppSettings["dsn"]); cmd = new SqlCommand("Sp_Area_SelectAllWhereProvince",conn); cmd.CommandType = CommandType.StoredProcedure; cmd.Parameters.Add("@Province",SqlDBType.VarChar,50).Value = a.ToString(); conn.Open(); dr = cmd.ExecuteReader(CommandBehavior.CloseConnection); return dr; } } } drop procedure [dbo].[Sp_Area_SelectAll] GO if exists (select * from dbo.sysobjects where id = object_id(N’[dbo].[Sp_Area_SelectAllWhereProvince]’) and OBJECTPROPERTY(id, N’IsProcedure’) = 1) drop procedure [dbo].[Sp_Area_SelectAllWhereProvince] GO if exists (select * from dbo.sysobjects where id = object_id(N’[dbo].[Area]’) and OBJECTPROPERTY(id, N’IsUserTable’) = 1) drop table [dbo].[Area] GO CREATE TABLE [dbo].[Area] ( [ID] [int] NOT NULL , [Province] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL , [City] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL , [其它] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ) ON [PRIMARY] GO SET QUOTED_IDENTIFIER ON GO SET ANSI_NULLS ON GO CREATE PROCEDURE Sp_Area_SelectAll AS SELECT DISTINCT Province FROM Area ORDER BY Province RETURN GO SET QUOTED_IDENTIFIER OFF GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_NULLS ON GO CREATE PROCEDURE Sp_Area_SelectAllWhereProvince @Province varchar(50) AS SELECT Area.* FROM Area WHERE (Province = @Province) RETURN GO SET QUOTED_IDENTIFIER OFF GO SET ANSI_NULLS ON GO ================================================〉 using System; using System.Data; using System.Data.SqlClient; using System.Configuration; namespace Db { ///

/// Base 的摘要说明。 ///

public class Base { public Base() { // // TODO: 在此处添加构造函数逻辑 // } protected string con = ConfigurationSettings.AppSettings["dsn"]; protected SqlConnection conn; protected SqlCommand cmd; protected SqlDataReader dr; protected string strSp; protected SqlDataReader drSelectAll(string strSp) { conn = new SqlConnection(con); cmd = new SqlCommand(strSp,conn); cmd.CommandType = CommandType.StoredProcedure; conn.Open(); dr = cmd.ExecuteReader(CommandBehavior.CloseConnection); return dr; }//返回一个SqlDataReader } }