.NET中实现无刷新客户端联动下拉菜单 (无刷新) (转帖)

2019-11-17 04:07:41

字体：大中小

来源：转载

供稿：网友

<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="CustomManager.company.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
  <title>WebForm1</title>
  <meta content="Microsoft Visual Studio .NET 7.1" name="GENERATOR">
  <meta content="C#" name="CODE_LANGUAGE">
  <meta content="javaScript" name="vs_defaultClientScript">
  <meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
  <LINK href="../CSS/style.css" type="text/css" rel="stylesheet">
</HEAD>
<body MS_POSITIONING="GridLayout">
  <form id="Form1" method="post" runat="server">
   <asp:dropdownlist id="DropDownList1" style="Z-INDEX: 101; LEFT: 40px; POSITION: absolute; TOP: 168px"
    runat="server"></asp:dropdownlist>


<asp:label id="Label1" style="display:none;" runat="server">Label</asp:label>

   <asp:DropDownList id="DropDownList2" style="Z-INDEX: 104; LEFT: 40px; POSITION: absolute; TOP: 264px"
    runat="server"></asp:DropDownList></form>
<script LANGUAGE="Javascript">
//将隐藏的字符串取出来，然后分割到一个数组中去
var str = document.getElementById("Label1").innerText;
arr=str.split(",");
a=arr.length
ar=new Array()
for (i=0;i<a;i++){
  ar[i]=arr[i].split("-");
}
onecount=ar.length;

//此处实现联动
function  ld() {
  document.Form1.DropDownList2.length=0
  lid=Form1.DropDownList1.value;
  for  (i=0;i<onecount;i++)  {
    if  (ar[i][0]  ==  lid) {
   document.Form1.DropDownList2.options.add(new Option(ar[i][2],  ar[i][1]));
    }
  }
}

function showMsg()
{
alert(document.Form1.DropDownList1.value);
alert(document.Form1.DropDownList2.value);
}

  </script>
</body>
</HTML>

以下是WebForm1.aspx.cs

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;

namespace CustomManager.company
{
/// <summary>
/// WebForm1 的摘要说明。
/// </summary>
public class WebForm1 : System.Web.UI.Page
{
  PRotected System.Web.UI.WebControls.DropDownList DropDownList1;
  protected System.Web.UI.WebControls.Label Label1;
  protected System.Web.UI.WebControls.DropDownList DropDownList2;
  static protected DataTable tb1;

  private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此处放置用户代码以初始化页面

   if(!Page.IsPostBack)
   {

   }

//给DropDownList1设置onchange事件
   DropDownList1.Attributes.Add("onchange","ld();");
   string strConn,strSql;
   System.Data.SqlClient.SqlDataAdapter da;


//从数据库中取出一级栏目，绑定到     DropDownList1
strConn = "server=localhost;database=custom;uid=custom;pwd=a;";
   strSql = "select * from custom.bigcalling;";
   da = new System.Data.SqlClient.SqlDataAdapter(strSql,strConn);
   DataTable tb3 = new DataTable();
   da.Fill(tb3);

   DropDownList1.DataSource = tb3;
   DropDownList1.DataTextField = "BIGCALLNAME";
   DropDownList1.DataValueField= "BIGCALLID";
   DropDownList1.DataBind();

//取出二级栏目数据，存放到一个DataTable()中
   strSql = "select * from custom.smallcalling;";
   da = new System.Data.SqlClient.SqlDataAdapter(strSql,strConn);
   tb1 = new DataTable();
   da.Fill(tb1);

//以下就是将一级和二级菜单的内容，分别以"-"和","隔开
//然后存放到 Label1中,这样客户端就可以通过脚本取得所需要的数据了
   Label1.Text = "";

   foreach(DataRow row in tb1.Rows)
   {
    Label1.Text = Label1.Text  + row["BIGCALLID"] + "-" +row["SMALLCALLID"] + "-"+row["SMALLCALLNAME"] + ",";

   }

  }

  #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);
  }

  /// <summary>
  /// 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。
  /// </summary>
  private void InitializeComponent()
  {
   this.Load += new System.EventHandler(this.Page_Load);

  }
  #endregion


}
}

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