ListBox控件例子

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="ListBox.aspx.cs" Inherits="WebApplication1.ListBox" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <asp:ListBox ID="listUsers" runat="server" SelectionMode="Multiple"></asp:ListBox>
    <asp:Button  ID="btnOK" runat="server" Text="确定" onclick="btnOK_Click" />
    </div>
    </form>
</body>
</html>

CS:

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 WebApplication1
{
    public partial class ListBox : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                BindUserList();
            }
        }
        private void BindUserList()
        {
            SqlConnection conn = new SqlConnection(@"server=Rose-PCSQLEXPRESS;Database=User;User Id=sa;password=");
            SqlCommand command = new SqlCommand("Select ID,RealName from UserInfo", conn);
            SqlDataAdapter adapter = new SqlDataAdapter(command);
            DataTable data = new DataTable();
            adapter.Fill(data);

            listUsers.DataTextField = "RealName";
            listUsers.DataValueField = "ID";
            listUsers.DataSource = data;
            listUsers.DataBind();
        }

        protected void btnOK_Click(object sender, EventArgs e)
        {
            string selectedUserName = string.Empty;
            //遍历ListBox中的每一个选项
            foreach (ListItem item in listUsers.Items)
            {
                //如果项被选中
                if (item.Selected)
                {
                    selectedUserName += item.Value + ",";
                }
            }
            //至少有一项被选中
            if (!string.IsNullOrEmpty(selectedUserName))
            {
                //删除最后一个“,”符号
                selectedUserName = selectedUserName.Remove(selectedUserName.Length - 1);
            }
            Response.Write("你选择的用户编号有:"+selectedUserName);
        
        }
    }
}
原文地址:https://www.cnblogs.com/ai394495243/p/3355864.html