Ajax实现在textbox中输入内容,动态从数据库中模糊查询显示到下拉框中

功能:在textbox中输入内容,动态从数据库模糊查询显示到下拉框中,以供选择
  1.建立一aspx页面,html代码
  <HTML>
   <HEAD>
   <title>WebForm1</title>
   <SCRIPT language="javascript">
   //城市------------------------------
   function cityResult()
   {
   var city=document.getElementById("TextBox1");
   WebForm1.GetCityList(city.value,get_city_Result_CallBack);
   }
  
   function get_city_Result_CallBack(response)
   {
   if (response.value != null)
   {
   //debugger;
   document.getElementById("DropDownList1").style.display="block";
   document.getElementById("DropDownList1").length=0;
   var ds = response.value;
   if(ds != null && typeof(ds) == "object" && ds.Tables != null)
   {
   for(var i=0; i<ds.Tables[0].Rows.length; i++)
   {
   var name=ds.Tables[0].Rows[i].city;
   var id=ds.Tables[0].Rows[i].cityID;
   document.getElementById("DropDownList1").options.add(new Option(name,id));
   }
   }
   }
   else
   {
   document.getElementById("DropDownList1").style.display="none";
   }
   return
   }
  
   function getData()
   {
   var province=document.getElementById("DropDownList1");
   var pindex = province.selectedIndex;
   var pValue = province.options[pindex].value;
   var pText = province.options[pindex].text;
   document.getElementById("<%=TextBox1.ClientID%>").innerText=pText;
   }
   </SCRIPT>
   </HEAD>
   <body>
   <form id="Form1" method="post" runat="server">
   <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
   <br>
   <asp:DropDownList ID="DropDownList1" runat="server" Width="192px" style="display:none"></asp:DropDownList>
   </form>
   </body>
  </HTML>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;
  using System.Data.SqlClient;
  namespace ajaxselect
  {
   /**//// <summary>
   /// Summary description for WebForm1.
   /// </summary>
   public class WebForm1 : System.Web.UI.Page
   {
   protected System.Web.UI.WebControls.TextBox TextBox1;
   protected System.Web.UI.WebControls.DropDownList DropDownList1;
  
   private void Page_Load(object sender, System.EventArgs e)
   {
   Ajax.Utility.RegisterTypeForAjax(typeof(WebForm1));
   if (!Page.IsPostBack)
   {
   this.TextBox1.Attributes.Add("onchange", "cityResult();");
   this.DropDownList1.Attributes.Add("onclick", "getData();");
   }
   }
   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);
   }
  
   /**//// <summary>
   /// Required method for Designer support - do not modify
   /// the contents of this method with the code editor.
   /// </summary>
   private void InitializeComponent()
   {
   this.Load += new System.EventHandler(this.Page_Load);
   }
   #endregion
   GetCityList#region GetCityList
   [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
   public DataSet GetCityList(int provinceid)
   {
   string sql = "select * from city where father like '%" + provinceid + "%'";
   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
   }
  }3.源代码下载
  4.数据库脚本
  CREATE TABLE [dbo].[city](
   [id] [int] NOT NULL,
   [cityID] [nvarchar](6) COLLATE Chinese_PRC_CI_AS NULL,
   [city] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL,
   [father] [nvarchar](6) COLLATE Chinese_PRC_CI_AS NULL,
  CONSTRAINT [PK_city] PRIMARY KEY CLUSTERED
  (
   [id] ASC
  )WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
  ) ON [PRIMARY](王朝网络 wangchao.net.cn)

原文地址:https://www.cnblogs.com/ayforver/p/3491972.html