asp.net DropDownList值上下移动
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!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:DropDownList ID="DropDownList1" runat="server" Style="width: 200px;" size="5">
<asp:ListItem>上海</asp:ListItem>
<asp:ListItem>北京</asp:ListItem>
<asp:ListItem>深圳</asp:ListItem>
<asp:ListItem>广州</asp:ListItem>
</asp:DropDownList>
<br />
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="上移动" />
<asp:Button ID="Button2" runat="server" onclick="Button2_Click" Text="下移动" />
</div>
</form>
</body>
</html>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{//上移动
int index = this.DropDownList1.SelectedIndex;
if (index > 0)
{//索引不能从第一个开始上移
ListItem item = this.DropDownList1.Items[index];
this.DropDownList1.Items.RemoveAt(index);
this.DropDownList1.Items.Insert(index - 1, item);
}
}
protected void Button2_Click(object sender, EventArgs e)
{//下移动
int index = this.DropDownList1.SelectedIndex;
if (index < DropDownList1.Items.Count - 1)
{//索引不能从最后一个下移 索引下标是从0开始 所以count-1
ListItem item = this.DropDownList1.Items[index];
this.DropDownList1.Items.RemoveAt(index);
this.DropDownList1.Items.Insert(index + 1, item);
}
}
}
原始效果
移动效果
