aspx页面：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="上传和下载文件.aspx.cs" Inherits="上传和下载文件" %> <!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> </head> <body> <form id="form1" runat="server"> <asp:FileUpload ID="homeworkFile" runat="server" /> <asp:Button ID="btnAdd" runat="server" Text="上传" OnClick="btnAdd_Click"/></br> <asp:Button ID="btndownfile" runat="server" Text="下载方法一：TransmitFile" onclick="btndownfile_Click" /></br> <asp:Button ID="btndownfilebyWriteFile" runat="server" Text="下载方法二：WriteFile" onclick="btndownfilebyWriteFile_Click" /></br> <asp:Button ID="btndownfilebyWriteFile2" runat="server" Text="下载方法三：WriteFile分块" onclick="btndownfilebyWriteFile2_Click" /><br /> <asp:Button ID="btndownfilebystream" runat="server" Text="下载方法四：流方式下载" onclick="btndownfilebystream_Click" /> </form> </body> </html>
aspx后台代码：
using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.IO; public partial class 上传和下载文件 : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void btnAdd_Click(object sender, EventArgs e) { //文件原名 string fileName = Path.GetFileName(this.homeworkFile.FileName); //文件新名字=文件原名+当前时间 string newFileName = fileName.Substring(0, fileName.IndexOf('.')) + DateTime.Now.ToString("yyyyMMddhhmmss"); //给文件名加后缀名 newFileName += fileName.Substring(fileName.IndexOf('.'), fileName.Length - fileName.IndexOf('.')); //获得文件存储的路径名 string Url = ConfigurationManager.AppSettings["ResoursePath"] + ConfigurationManager.AppSettings["RESHomeworkContentPath"] + @"" + newFileName; //验证文件大小 if (this.IsFileSizeLessMax()) { //验证文件的类型 if (this.isTypeOk(Url)) { //验证文件存储的路径是否存在 string pathStr = ConfigurationManager.AppSettings["ResoursePath"] + ConfigurationManager.AppSettings["RESHomeworkContentPath"]; if (!Directory.Exists(pathStr)) //如果不存在路径 { Directory.CreateDirectory(pathStr); //创建路径 } if (!Url.Equals("")) //如果有上传文件 { FileUpload fileUpLoad = new FileUpload(); //1.存放文件 // fileUpLoad.SaveAs(Url); homeworkFile.PostedFile.SaveAs(Url); } } } } /// <summary> /// 验证上传文件是否超过规定的最大值 /// </summary> /// <returns></returns> private bool IsFileSizeLessMax() { //返回值 bool result = false; if (this.homeworkFile.HasFile) //如果上传了文件 { //获取上传文件的允许最大值 long fileMaxSize = 1024 * 1024; try { fileMaxSize *= int.Parse(ConfigurationManager.AppSettings["FileUploadMaxSize"].Substring(0, ConfigurationManager.AppSettings["FileUploadMaxSize"].Length - 1)); } catch (Exception ex) { //this.WriteException("UserPotal:Homework", ex); } if (this.homeworkFile.PostedFile.ContentLength > int.Parse(fileMaxSize.ToString())) //如果文件大小超过规定的最大值 { //this.ShowMessage("文件超过规定大小。"); } else { result = true; } } else //如果没有上传的文件 { result = true; } return result; } /// <summary> /// 验证文件类型的方法 /// </summary> /// <param name="fileName"></param> /// <returns></returns> private bool isTypeOk(string fileName) { //返回结果 bool endResult = false; //验证结果 int result = 0; if (!fileName.Equals("")) //如果有上传文件 { //允许的文件类型 string[] fileType = null; try { fileType = ConfigurationManager.AppSettings["FileType"].Split(','); } catch (Exception ex) { //this.ShowMessage("获取配置文件信息出错"); //this.WriteException("AdminProtal:Homework", ex); } fileName = fileName.Substring(fileName.LastIndexOf('.'), fileName.Length - fileName.LastIndexOf('.')); for (int i = 0; i < fileType.Length; i++) { if (fileType[i].Equals(fileName)) //如果是合法文件类型 { result++; } } if (result > 0) { endResult = true; } } else //如果没有上传文件 { endResult = true; } return endResult; } //下载方法一 protected void btndownfile_Click(object sender, EventArgs e) { /* 微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite 下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。 代码如下： */ Response.ContentType = "application/x-zip-compressed"; Response.AddHeader("Content-Disposition", "attachment;filename=DBintegrate20120521030107.txt"); string filename = Server.MapPath("BJNetwork/Data/DBintegrate20120521030107.txt"); Response.TransmitFile(filename); } //下载方法二 protected void btndownfilebyWriteFile_Click(object sender, EventArgs e) { /* using System.IO; */ string fileName = "DBintegrate20120521030107.txt";//客户端保存的文件名 string filePath = Server.MapPath("BJNetwork/Data/DBintegrate20120521030107.txt");//路径 FileInfo fileInfo = new FileInfo(filePath); Response.Clear(); Response.ClearContent(); Response.ClearHeaders(); Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName); Response.AddHeader("Content-Length", fileInfo.Length.ToString()); Response.AddHeader("Content-Transfer-Encoding", "binary"); Response.ContentType = "application/octet-stream"; Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312"); Response.WriteFile(fileInfo.FullName); Response.Flush(); Response.End(); } //下载方法三 protected void btndownfilebyWriteFile2_Click(object sender, EventArgs e) { string fileName = "前台老师和学生界面对比20120521034329.rar";//客户端保存的文件名 string filePath = Server.MapPath("BJNetwork/Data/前台老师和学生界面对比20120521034329.rar");//路径 System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath); if (fileInfo.Exists == true) { const long ChunkSize = 102400;//100K 每次读取文件，只读取100K，这样可以缓解服务器的压力 byte[] buffer = new byte[ChunkSize]; Response.Clear(); System.IO.FileStream iStream = System.IO.File.OpenRead(filePath); long dataLengthToRead = iStream.Length;//获取下载的文件总大小 Response.ContentType = "application/octet-stream"; Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName)); while (dataLengthToRead > 0 && Response.IsClientConnected) { int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小 Response.OutputStream.Write(buffer, 0, lengthRead); Response.Flush(); dataLengthToRead = dataLengthToRead - lengthRead; } Response.Close(); } } //下载方法四 protected void btndownfilebystream_Click(object sender, EventArgs e) { string fileName = "前台老师和学生界面对比20120521034329.rar";//客户端保存的文件名 string filePath = Server.MapPath("BJNetwork/Data/前台老师和学生界面对比20120521034329.rar");//路径 //以字符流的形式下载文件 FileStream fs = new FileStream(filePath, FileMode.Open); byte[] bytes = new byte[(int)fs.Length]; fs.Read(bytes, 0, bytes.Length); fs.Close(); Response.ContentType = "application/octet-stream"; //通知浏览器下载文件而不是打开 Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)); Response.BinaryWrite(bytes); Response.Flush(); Response.End(); } }
web配置文件：
<appSettings>
<!--上传文件的路径-->
<add key="ResoursePath" value="D:IbeaconShowBJNetwork"/>
<add key="RESHomeworkContentPath" value="Data"/>
<!--可上传文件的大小-->
<add key="FileUploadMaxSize" value="20M"/>
<!--可上传文件类型 -->
<add key="FileType" value=".zip,.txt,.doc,.rar,.xls,.rtf,.xlsx,.docx,.png"/>
</appSettings>
<system.web>
<!--修改asp.net默认上传文件的大小-->
<httpRuntime executionTimeout="300" maxRequestLength="409600" useFullyQualifiedRedirectUrl="false"/>
</system.web>
IIS中上传大小的修改
1、首先要到进程中把IIS服务关了，即把inetinfo.exe进程关了，不然里面的文件不给你更改的哟~~~
2、在系统目录中找到：windows/system32/inesrv/metabase.xml”文件，找个文本编辑器打开他，我都用EditPuls（这家伙不错，带字体色彩的），Ctrl+F 找到AspMaxRequestEntityAllowed="204800"这一项，这就是iis上传文件的默认大小了，默认为204800Byte，也就是200KB，将它改为你需要的大小就可以了！