前台代码：Default.aspx 注意：一定要在<form id="form1" runat="server" enctype="multipart/form-data">
<%@ 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>无标题页</title> <script language="javascript" type="text/javascript"> function AddFile()
{
var strFile='<input name="File1" type="file" /><br />'; document.getElementById("DivFile").insertAdjacentHTML("beforeEnd",strFile);
} </script> </head><body> <form id="form1" runat="server" enctype="multipart/form-data"> <div> <div id="DivFile"><input name="File1" type="file" /><br /> </div> <input id="Button2" type="button" value="增加" onclick="return AddFile();" /> <asp:Button ID="Button1" runat="server" Text="上传" OnClick="Button1_Click" /><br /> </div> </form></body></html>后台代码：Default.aspx.cs
using System;using System.Data;using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.IO;using System.Text;public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e)
{
} protected void Button1_Click(object sender, EventArgs e) { //这是第一种写法了 ////定义上传文件的列表 //HttpFileCollection fileList = HttpContext.Current.Request.Files; ////存放上传文件的操作信息 //StringBuilder strMessage = new StringBuilder("当前上传的文件分别是:<hr color=red>"); //try //{ // //上传文件列表中的每一个文件 // for (int i = 0; i < fileList.Count; i++) // { // //取得当前上传的文件 // HttpPostedFile postedFile = fileList[i]; // string fileName; // string fileExtension; // //获取上传文件的文件名 // if (postedFile.ContentLength > 0) // { // fileName = Path.GetFileName(postedFile.FileName); // fileExtension = Path.GetExtension(fileName); // strMessage.Append("上传文件类型：" + postedFile.ContentType.ToString() + "<br />"); // strMessage.Append("客户端文件地址：" + postedFile.FileName + "<br/>"); // strMessage.Append("上传文件的文件名：" + fileName + "<br/>"); // strMessage.Append("上传文件的扩展名：" + fileExtension + "<br/></hr>"); // string path = Server.MapPath("files\\") + fileName; // postedFile.SaveAs(path); // Response.Write(strMessage.ToString()); // } // else // { // Response.Write("不能上传空文件"); // } // } //} //catch (Exception ex) //{ // throw ex; //} StringBuilder strMessage = new StringBuilder(); HttpFileCollection fileList = HttpContext.Current.Request.Files; for (int i = 0; i < fileList.Count; i++) { HttpPostedFile postedFile = fileList[i]; if (postedFile.ContentLength > 0) { string FileName = postedFile.FileName; string FileExtension = FileName.Substring(FileName.LastIndexOf(".") + 1); string[] NoFileExtension = { "exe", "asp", "php" }; bool IsUp = true; for (int j = 0; j < NoFileExtension.Length; j++) { if (FileExtension.Equals(NoFileExtension[j])) { IsUp = false; } } if (IsUp) { //循环时在文件名后面加变量i，防止同时传相同类型的文件时，后一个文件覆盖前一个文件 string sFilePath = string.Format("files/{0}.{1}", DateTime.Now.ToString("mmhhddss")+i, FileExtension); postedFile.SaveAs(Server.MapPath(sFilePath)); strMessage.Append("文件上传成功！"); strMessage.Append(string.Format("{0}.{1}", DateTime.Now.ToString("mmhhddss")+i, FileExtension)); strMessage.Append("<br />"); strMessage.Append("文件的格式："); strMessage.Append(FileExtension+"<br />"); strMessage.Append("<br />```````````````<br />"); Response.Write("文件上传成功！" + "<br />文件名是：" + string.Format("{0}.{1}", DateTime.Now.ToString("mmhhddss")+i, FileExtension) + "<br />文件的格式：" + FileExtension); } else { Response.Write(string.Format("不允许上传{0}格式文件", FileExtension)); } } else { Response.Write("不能上传空文件"); } } } }