ListBox 列表框
autopostback:true:
if(!ispostback)
{ }1：绑定数据:
if(!IsPostBack) { NationDataContext context = new NationDataContext(); ListBox1.DataSource = context.Nation; ListBox1.DataTextField = "Name"; ListBox1.DataValueField = "Code"; ListBox1.DataBind(); }} 2:获取选中项的值 单选：Label1.Text= ListBox1.SelectedValue.ToString(); 多选:属性>selectionmode>mutiple可单选protected void Button1_Click(object sender, EventArgs e)
{foreach (ListItem item in ListBox1.Items)
{ if (item.Selected) { Label1.Text +=item.Value; }}
3:设置选中项protected void Button2_Click(object sender, EventArgs e)
{foreach (ListItem item in ListBox1.Items)
{ if (item.Text == "汉族" || item.Text == "满族") { item.Selected = true; }}
}
4：练习：
using System;
using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;public partial class lizi : System.Web.UI.Page
{//加载绑定数据
protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { NationDataContext context = new NationDataContext(); ListBox1.DataSource = context.Nation; ListBox1.DataTextField = "Name"; ListBox1.DataValueField = "Code"; ListBox1.DataBind(); } } //单选。多选 protected void Button1_Click(object sender, EventArgs e) { foreach (ListItem item in ListBox1.Items) { if (item.Selected) { if(! ListBox2.Items.Contains(item))//如果列表框2中不包含此数据则添加否则不添加，防止重复添加 { ListBox2.Items.Add(item); }}
}
}//全选
protected void Button2_Click(object sender, EventArgs e) { foreach (ListItem item in ListBox1.Items) { if (!ListBox2.Items.Contains(item))//如果列表框2中不包含此数据则添加否则不添加，防止重复添加 { ListBox2.Items.Add(item); }
}
}}