asp.net的文件上传都是单个文件上传方式，无法执行一次性多张图片批量上传操作，要实现多图片批量上传需要借助于flash，通过flash选取多个图片(文件)，然后再通过后端服务进行上传操作.
本次教程所使用的flash上传文件是 swfupload,下面会有源码下载链接。
使用工具 vs 2010。
演示效果图
第一步 新建一个web项目
第二步 引入所需swfuplod文件（swfupload.swf,js,css等)
第三步 新建一个一般处理程序(upload.ashx)
upload.ashx程序文件代码
using System;
using System.Collections.Generic;
using System.Web;
using System.IO;
namespace yuyue.upload
{
/// <summary>
/// upload 的摘要说明
/// </summary>
public class upload : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
try
{
HttpPostedFile file;
for (int i = 0; i < context.Request.Files.Count; ++i)
{
file = context.Request.Files[i];
if (file == null || file.ContentLength == 0 || string.IsNullOrEmpty(file.FileName)) continue;
string filename = DateTime.Now.ToString("yyyyMMddHHmmss") + RndNumStr(6) + Path.GetExtension(file.FileName); //文件名=上传日期+随机字符串+扩展名（可避免多人上传是第一名问题)
/********************文件夹**************************/
string year=DateTime.Now.Year.ToString();
string monthday = DateTime.Now.ToString("MMdd");
if (!Directory.Exists(HttpContext.Current.Server.MapPath("/uploads/")+year))
{
Directory.CreateDirectory(HttpContext.Current.Server.MapPath("/uploads/") + year);
}
if (!Directory.Exists(HttpContext.Current.Server.MapPath("/uploads/") + year + "/" + monthday))
{
Directory.CreateDirectory(HttpContext.Current.Server.MapPath("/uploads/") + year + "/" + monthday);
}
file.SaveAs(HttpContext.Current.Server.MapPath("/uploads/" + year + "/" + monthday + "/" + filename));
context.Response.Write("/uploads/" + year + "/" + monthday + "/" + filename);//输出上传地址以用于前台js获取
}
}
catch (Exception ex)
{
context.Response.StatusCode = 500;
context.Response.Write(ex.Message);
context.Response.End();
}
finally
{
context.Response.End();
}
}
#region 该方法用于生成指定位数的随机字符串
/// <summary>
/// 该方法用于生成指定位数的随机字符串
/// </summary>
/// <param name="VcodeNum">参数是随机数的位数</param>
/// <returns>返回一个随机数字符串</returns>
public static string RndNumStr(int VcodeNum)
{
string[] source = { "0", "1", "1", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z" };
string checkCode = String.Empty;
Random random = new Random();
for (int i = 0; i < VcodeNum; i++)
{
checkCode += source[random.Next(0, source.Length)];
}
return checkCode;
}
#endregion
public bool IsReusable
{
get
{
return false;
}
}
}
}
第四步 新建一个web窗体(swfupload.aspx)
swfupload.aspx 文件源码
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="swfupload.aspx.cs" Inherits="yuyue.upload.swfupload" %>
<!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>文件上传</title>
<link href="/statics/js/swfupload/css.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="/statics/js/jquery-1.7.2.min.js"></script>
<script type="text/javascript" src="/statics/js/swfupload/swfupload.js"></script>
<script type="text/javascript" src="/statics/js/swfupload/swfupload.queue.js"></script>
<script type="text/javascript" src="/statics/js/swfupload/fileprogress.js"></script>
<script type="text/javascript" src="/statics/js/swfupload/filegroupprogress.js"></script>
<script type="text/javascript" src="/statics/js/swfupload/handlers.js"></script>
<asp:Literal ID="Literal1" runat="server"></asp:Literal>
<script type="text/javascript">
function album_cancel(obj,src) {
$(obj).toggleClass("on");
if ($(obj).hasClass("on")) {
$("#tb_imgurls").val($("#tb_imgurls").val() + src);
$("#piclists").val($("#piclists").val() + "<li><a href="" + src.toString().substring(0, src.length - 1) + "" title="点击图片查看大图" onclick="return hs.expand(this)"><img src='" + src.toString().substring(0, src.length - 1) + "' width='86' height='80' alt='点击图片查看大图'></a></li>");
}
else {
var str = $("#tb_imgurls").val();
var strpic = $("#piclists").val();
$("#tb_imgurls").val(str.replace(src, ''));
$("#piclists").val(strpic.replace("<li><a href="" + src.toString().substring(0, src.length - 1) + "" title="点击图片查看大图" onclick="return hs.expand(this)"><img src='" + src.toString().substring(0, src.length - 1) + "' width='86' height='80' alt='点击图片查看大图'></a></li>", ""));
}
}
function confirmupload() {
parent.$("#relaimg").val(parent.$("#relaimg").val()+$("#tb_imgurls").val());
parent.$(".piclist").html(parent.$(".piclist").html() + $("#piclists").val());
parent.TB_remove();
}
</script>
</head>
<body>
<form name="frmMain" method="post" action="upload.ashx" id="frmMain" enctype="multipart/form-data">
<div>
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwULLTE0MDkxNzYwNDNkZITPwV8CB9intILgmCGmWeJNXndY" />
</div>
<table cellpadding="5">
<tr>
<td style="padding:5px;"><span id="spanButtonPlaceHolder"></span></td>
<td style="padding:5px;"><span class="btn_upload" onclick='swfu.startUpload()'><img src="/statics/js/swfupload/images/swfBnt_upload.png" /></span></td>
<td style="padding:5px;"><div id="nameTip" class="onShow">最多上传<font color="red"> <asp:Literal ID="Literal2" runat="server"></asp:Literal></font> 个附件,单文件最大 <font color="red"><asp:Literal ID="Literal3" runat="server"></asp:Literal></font></div></td>
</tr>
<tr>
<td colspan="3" style="padding:5px;">支持 <asp:Literal ID="Literal4" runat="server"></asp:Literal>格式。</td>
</tr>
</table>
<div class="uploadbox">
<span class="uploadbox_t">列表</span>
<div id="divprogresscontainer"></div>
<div id="divprogressGroup"></div>
<div id="piclist">
<ul>
</ul>
</div>
</div>
<br /><br />
<input type="hidden" name="tb_imgurls" id="tb_imgurls" value=""/><br />
<input type="hidden" name="piclists" id="piclists" value=""/>
<div style="margin-left:300px;clear:both;">
<table>
<tr>
<!-- 此处是用于我项目Thickbox应用 可忽略-->
<td><div class="submit"><input type="button" value="确定" onclick="confirmupload()"/></div></td>
<td><div class="submit"><input type="button" value="取消" onclick="parent.TB_remove();" /></div> </td>
</tr>
<!-- end -->
</table>
</div>
</form>
</body>
</html>
swfupload.aspx.cs 文件源码
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace yuyue.upload
{
public partial class swfupload : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
//构造 swfupload.swf 所需js文件
Literal1.Text += "<script type="text/javascript">
";
Literal1.Text += " var swfu;
";
Literal1.Text += " window.onload = function () {
";
Literal1.Text += " var settings = {
";
Literal1.Text += " flash_url: "/statics/js/swfupload/swfupload.swf",
";
Literal1.Text += " upload_url: "upload.ashx",
";
if (Request.QueryString["file_size_limit"] != null)
{
Literal1.Text += " file_size_limit: "" + Request.QueryString["file_size_limit"] + "",
";//文件大小限制
Literal3.Text = Request.QueryString["file_size_limit"];
}
else
{
Literal1.Text += " file_size_limit: "2 MB",
";
Literal3.Text = "2 MB";//文件大小限制
}
if (Request.QueryString["file_types"] != null)
{
Literal1.Text += " file_types: "" + Request.QueryString["file_types"] + "",
";
Literal4.Text = Request.QueryString["file_types"];
}
else
{
Literal1.Text += " file_types: "*.*",
";
Literal4.Text = "*.*";
}
if (Request.QueryString["file_types_description"] != null)
{
Literal1.Text += " file_types_description: "" + Request.QueryString["file_types_description"] + "",
";
}
else
{
Literal1.Text += " file_types_description: "All Files",
";
}
if (Request.QueryString["file_upload_limit"] != null)
{
Literal1.Text += " file_upload_limit: " + Request.QueryString["file_upload_limit"] + ",
";
Literal2.Text = Request.QueryString["file_upload_limit"];
Literal2.Text = "50";
}
else
{
Literal1.Text += " file_upload_limit: 50,
";
}
Literal1.Text += " file_queue_limit: 0,
";
Literal1.Text += " autoremove: true, //是否自动移除完成上传的记录
";
Literal1.Text += " custom_settings: {
";
Literal1.Text += " progressTarget: "divprogresscontainer",
";
Literal1.Text += " progressGroupTarget: "divprogressGroup",
";
//progress object
Literal1.Text += " container_css: "progressobj",
";
Literal1.Text += " icoNormal_css: "IcoNormal",
";
Literal1.Text += " icoWaiting_css: "IcoWaiting",
";
Literal1.Text += " icoUpload_css: "IcoUpload",
";
Literal1.Text += " fname_css: "fle ftt",";
Literal1.Text += " state_div_css: "statebarSmallDiv",
";
Literal1.Text += " vstate_bar_css: "statebar",
";
Literal1.Text += " percent_css: "ftt",
";
Literal1.Text += " href_delete_css: "ftt",
";
//sum object
/*
页面中不应出现以"cnt_"开头声明的元素
*/
Literal1.Text += " s_cnt_progress: "cnt_progress",
";
Literal1.Text += " s_cnt_span_text: "fle",";
Literal1.Text += " s_cnt_progress_statebar: "cnt_progress_statebar",
";
Literal1.Text += " s_cnt_progress_percent: "cnt_progress_percent",
";
Literal1.Text += " s_cnt_progress_uploaded:"cnt_progress_uploaded",
";
Literal1.Text += " s_cnt_progress_size: "cnt_progress_size"
";
Literal1.Text += " },
";
Literal1.Text += " debug: false,
";
// Button settings
Literal1.Text += " button_image_url: "/statics/js/swfupload/images/swfBnt_select.png",
";
Literal1.Text += " button_ "75",
";
Literal1.Text += " button_height: "28",
";
Literal1.Text += " button_placeholder_id: "spanButtonPlaceHolder",
";
//button_cursor="HAND",
//button_text: '',
//button_text_style: ".theFont { font-size: 12;color:#0068B7;}",
//button_text_left_padding: 12,
//button_text_top_padding: 3,
// The event handler functions are defined in handlers.js
Literal1.Text += " file_queued_handler: fileQueued,
";
Literal1.Text += " file_queue_error_handler: fileQueueError,
";
Literal1.Text += " upload_start_handler: uploadStart,
";
Literal1.Text += " upload_progress_handler: uploadProgress,
";
Literal1.Text += " upload_error_handler: uploadError,
";
Literal1.Text += " upload_success_handler: uploadSuccess,
";
Literal1.Text += " upload_complete_handler: uploadComplete
";
//file_dialog_complete_handler: fileDialogComplete
Literal1.Text += " };
";
Literal1.Text += " swfu = new SWFUpload(settings);
";
Literal1.Text += "};
";
Literal1.Text += "</script>
";
}
}
}
}
下载源码
asp.net(c#)+flash(swfupload) 多图片批量上传源码下载
总结
swfupload 多文件上传可用于多种类型文件上传，这里只演示了图片，你可以自己扩展。
同理，swfupload是不依赖于某个平台或者语言的，同样可用于PHP，Java，Asp.net等多种语言，只要您弄清楚原理就可以随意扩展，如有什么不明白的可给我留言。