在Email系統中經常會上傳多個文件到服務器，用戶大多習慣一次上傳所有的文件，而不是逐個上傳，我們可以使用javascript動態地添加file元素到表單，然後在服務器端處理這些file
效果圖如下:
頁面代碼MutlileFileUpload.aspx如下:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="MutlileFileUpload.aspx.cs"
Inherits="MutlileFileUpload" %>
<!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>
<title>多文件上傳到服務器Demo</title>
<link href="css/writemail.css" rel="stylesheet" type="text/css" />
<script type="text/javascript">
<!--
var MAXFILES = 5; //文件計數器
var fileCount = 0;
function addAttach(noAlert) {
if (fileCount >= MAXFILES && !noAlert) { alert("最多隻能添加" + MAXFILES + "個附件！"); return; }
var fileSectionDiv = document.getElementById("files");
var fileItemDiv = document.createElement("div");
fileCount++;
var content = "<input type='file' οnchange='return addAttach(true);' name='fileUpload'" + fileCount + "> <a href='#' οnclick='return delAttach(\"" + fileCount + "\")' class='delete_attach' >移除附件</a>";
fileItemDiv.id = "fileItemDiv" + fileCount;
fileItemDiv.innerHTML = content;
fileSectionDiv.appendChild(fileItemDiv);
return false;
}
function delAttach(fileIndex) {
var fileSectionDiv = document.getElementById("files");
var fileItemDiv = document.getElementById("fileItemDiv" + fileIndex);
fileSectionDiv.removeChild(fileItemDiv);
fileCount--;
return false;
} //
--></script>
</head>
<body>
<form id="form1" runat="server">
<div>
<a id="addAttach_a" οnclick="return addAttach(false);" href="#" class="add_attach">添加附件</a>
<div id="files">
</div>
<asp:Button ID="btnSend" runat="server" Text="發送" OnClick="btnSend_Click" />
</div>
</form>
</body>
</html>
樣式表WriteMail.css代碼如下:
.delete_attach {PADDING-LEFT: 18px; BACKGROUND: url(../images/deleteattch_icon.gif) no-repeat left top; MARGIN-LEFT: 7px; WIDTH: 90px; COLOR: #002f76}.add_attach {PADDING-LEFT: 22px; BACKGROUND: url(../images/attach.gif) no-repeat left center; WIDTH: 90px; COLOR: #002f76}
後臺代碼MutlileFileUpload.aspx.cs如下:
using System;
using System.IO;
using System.Web.UI;
public partial class MutlileFileUpload : System.Web.UI.Page
{
protected void Page_Load(object sender, System.EventArgs e)
{ //告訴表單如何格式化文件信息
Page.Form.Enctype = "multipart/form-data";
}
protected void btnSend_Click(object sender, EventArgs e)
{
for (int index = 0; index < Request.Files.Count; index++)
{
if (!string.IsNullOrEmpty(Request.Files[index].FileName))
{
Request.Files[index].SaveAs(Path.Combine(Server.MapPath("Files"), System.IO.Path.GetFileName(Request.Files[index].FileName)));
}
}
}
}