步步为营-70-asp.net简单练习(文件的上传和下载)
大文件的上传一般通过FTP协议,而一般小的文件可以通过http协议来完成
1 通过asp.net 完成图片的上传
1.1 创建html页面
注意:1 method="post" ;2 enctype="multipart/form-data"; 3 <input type="file" />
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title></title> </head> <body> <form method="post" action="FileUpload.ashx" enctype="multipart/form-data"> <input type="file" id="imgUpLoad" name="imgUpLoad" /> <input type="submit" value="提交" /> </form> </body> </html>
1.2 创建一般处理程序.ashx
注意:1 创建文件保存路径
using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Web; namespace _05_文件的上传与下载 { /// <summary> /// FileUpload 的摘要说明 /// </summary> public class FileUpload : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/html"; //01 获取文件 HttpPostedFile pf = context.Request.Files["imgUpLoad"]; //02 创建文件保存路径 string savePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory+"Upload/"+pf.FileName); //03 保存文件 pf.SaveAs(savePath); //04 显示上传的文件 context.Response.Write("<img src='Upload/"+pf.FileName+"'/> "); } public bool IsReusable { get { return false; } } } }
2 上传文件格式的验证,假设规定只能上传,gif的图片
我们可以在HTML通过jQuery来进行验证,也可以在.ashx中进行验证
2.1 修改ashx文件
using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Web; namespace _05_文件的上传与下载 { /// <summary> /// FileUpload 的摘要说明 /// </summary> public class FileUpload : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/html"; //01 获取文件 HttpPostedFile pf = context.Request.Files["imgUpLoad"]; //01-01 获取文件后缀名 string extName = pf.FileName.Substring(pf.FileName.LastIndexOf('.')); if (extName != ".gif" || extName != ".Gif") { context.Response.Write("请上传.gif图片"); return; } //02 创建文件保存路径 string savePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory+"Upload/"+pf.FileName); //03 保存文件 pf.SaveAs(savePath); //04 显示上传的文件 context.Response.Write("<img src='Upload/"+pf.FileName+"'/> "); } public bool IsReusable { get { return false; } } } }
2.2 引入jQuery,修改HTML页面
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <script src="http://localhost:62225/Script/jquery-1.7.1.min.js"></script> <title></title> <script> $(function () { $("form").submit(function () { var fname = $("#imgUpLoad").val(); var extname = fname.substring(fname.lastIndexOf('.')); if (extname != ".gif" || extname != ".Gif") { alert("请上传.gif图片"); return false; } }); }); </script> </head> <body> <form method="post" action="FileUpload.ashx" enctype="multipart/form-data"> <input type="file" id="imgUpLoad" name="imgUpLoad" /> <input type="submit" value="提交" /> </form> </body> </html>
3 如果文件只放在Upload文件夹下,随着时间的增长,文件势必会越来越多不利于寻找,可以根据日期建立相应文件夹
using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Web; namespace _05_文件的上传与下载 { /// <summary> /// FileUpload 的摘要说明 /// </summary> public class FileUpload : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/html"; //01 获取文件 HttpPostedFile pf = context.Request.Files["imgUpLoad"]; //01-01 获取文件后缀名 string extName = pf.FileName.Substring(pf.FileName.LastIndexOf('.')); if (extName != ".gif" && extName != ".GIF") { context.Response.Write("请上传.gif图片"); return; } //02 创建文件保存路径 string savePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory+"Upload\\"); //02-01 根据日期创建文件夹 DateTime dt = DateTime.Now; savePath += dt.Year + "\\" + dt.Month + "\\" + dt.Day ; if (!Directory.Exists(savePath)) { //创建文件夹 Directory.CreateDirectory(savePath); } //02-02文 件名为当前时间 savePath += "\\"+ dt.ToString().Replace(':','-')+".gif"; //03 保存文件 pf.SaveAs(savePath); //04 显示上传的文件 context.Response.Write("<img src='" + savePath.Substring(savePath.IndexOf("Upload")) + "'/> "); } public bool IsReusable { get { return false; } } } }
4 文件下载
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title></title> </head> <body> <img src="" /> <a href="FileDownload.ashx?f=Upload/2017.rar">Upload/2017.rar</a> <a href="FileDownload.ashx?f=Upload/2017-06-14%2017-25-19.gif">Upload/2017-06-14%2017-25-19.gif</a> </body> </html>
using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Web; namespace _05_文件的上传与下载 { /// <summary> /// FileDownload 的摘要说明 /// </summary> public class FileDownload : IHttpHandler { public void ProcessRequest(HttpContext context) { string f = context.Request["f"]; context.Response.ContentType = "application/octet-stream"; context.Response.AddHeader("Content-Disposition","attachment;filename=\""+f+"\";"); context.Response.WriteFile(Path.Combine(AppDomain.CurrentDomain.BaseDirectory,f)); } public bool IsReusable { get { return false; } } } }
