文件上传是最常用的B/S项目功能，在FileUpload控件出来之前只能使用html控件的File控件，这样在form中就需要加入【 enctype="multipart/form-data"】。
实例如下，
up2.aspx代码
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="up2.aspx.cs" Inherits="up2" %> <!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> </head> <body> <form id="form1" runat="server" enctype="multipart/form-data"> <input name="File" type="file" /> <asp:Button ID="Button1" runat="server" CssClass="button" OnClick="Button1_Click" Text="上传" /> </form> </body> </html>
up2.aspx.cs代码
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.IO; public partial class up2 : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void Button1_Click(object sender, EventArgs e) { string upPath = "/up/"; //上传文件路径 int upLength = 5; //上传文件大小 string upFileExtName = "|bmp|jpg|jpeg|png|gif|"; HttpFileCollection _files = System.Web.HttpContext.Current.Request.Files; for (int i = 0; i < _files.Count; i++) { string name = _files[i].FileName; FileInfo fi = new FileInfo(name); string oldfilename = fi.Name; string scExtension = fi.Extension.ToLower(); string fileName = DateTime.Now.ToString("yyyyMMddhhmmssfff") + fi.Extension; // 文件名称，当前时间（yyyyMMddhhmmssfff） string webFilePath = Server.MapPath(upPath) + fileName; // 服务器端文件路径 if (upFileExtName.IndexOf(scExtension.Replace(".", "")) == -1) { ClientScript.RegisterStartupScript(this.GetType(), "upfileOK", "alert('提示：文件类型不符" + scExtension + "');", true); return; } if ((fi.Length / (1024 * 1024)) > upLength) { ClientScript.RegisterStartupScript(this.GetType(), "upfileOK", "alert('大小超出 " + upLength + " M的限制，请处理后再上传！');", true); return; } try { _files[i].SaveAs(webFilePath); ClientScript.RegisterStartupScript(this.GetType(), "upfileOK", "alert('提示：文件上传成功');", true); } catch (Exception ex) { ClientScript.RegisterStartupScript(this.GetType(), "upfileOK", "alert('提示：文件上传失败" + ex.Message + "');", true); } } } }