<?xml version="1.0" encoding="utf-8" ?> 
<SystemVersion> 
<Item> 
<Version_ID>1</Version_ID> 
<Version_Name>CN</Version_Name> 
</Item> 
<Item> 
<Version_ID>2</Version_ID> 
<Version_Name>EN</Version_Name> 
</Item> 
</SystemVersion> 
用户控件的关键代码: 
SystemVersion.ascx 
复制代码 代码如下:
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="SystemVersion.ascx.cs" Inherits="UserControls_SystemVersion" %> 
<!-- Value是传入的值 --> 
<div> 
<asp:DropDownList runat="server"> 
</asp:DropDownList> 
</div> 
后台文件:
复制代码 代码如下:
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Data; 
using System.Xml; 
using System.Xml.Linq; 
public partial class UserControls_SystemVersion : System.Web.UI.UserControl 
{ 
private const string CON_FilePath = "~/App_Data/sysVersion.xml"; 
//// <summary> 
/// 下拉框赋值 
/// </summary> 
public string Value 
{ 
set { ViewState["Value"] = value; } 
get { return ViewState["Value"] == null ? null : ViewState["Value"].ToString().Trim(); } 
} 
protected void Page_Load(object sender, EventArgs e) 
{ 
if (!IsPostBack) 
{ 
DdlBind(); 
} 
} 
public void DdlBind() 
{ 
XElement xDoc = XElement.Load(Server.MapPath(CON_FilePath)); 
// Create the query 
var lVersion = from c in xDoc.Descendants("Item") 
where c.Element("Version_ID").Value == "1" //目前只显示CN 
select new 
{ 
Version_Name = c.Element("Version_Name").Value, 
Version_ID = c.Element("Version_ID").Value 
}; 
ddlVersion.DataSource = lVersion.ToList(); 
ddlVersion.DataTextField = "Version_Name"; 
ddlVersion.DataValueField = "Version_Name"; 
ddlVersion.DataBind(); 
if (Value != null) 
{ 
ddlVersion.SelectedValue=Value; 
} 
} 
}