转载地址：http://www.cnblogs.com/scy251147/archive/2010/09/30/1839313.html
官网链接：http://www.fyneworks.com/jquery/multifile/
具体方式是：
首先需要有jquery.js 其次要有jquery.MultiFile.js这两个文件
前台代码：
<%@ 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> <script src="jquery.js" type="text/javascript"></script> <script src="jquery.MultiFile.js" type="text/javascript"></script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:FileUpload ID="FileUpload1" runat="server" class="multi" />
<asp:Button ID="Button1" runat="server" Text="上传" onclick="Button1_Click"
Width="70px" />
</div>
</form>
</body>
</html>
后台代码：
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)
{
try
{
HttpFileCollection hfc = Request.Files;
for (int i = 0; i < hfc.Count; i++)
{
HttpPostedFile hpf=hfc[i];
if (hpf.ContentLength > 0)
{
hpf.SaveAs(Server.MapPath("Files")+"\\"+System.IO.Path.GetFileName(hpf.FileName));
Response.Write("文件："+hpf.FileName+"大小："+hpf.ContentLength+"类型："+hpf.ContentType+"上传成功！<br>");
}
}
}
catch { }
}
}