图1 文件上传前

图2 文件上传后

具体代码如下：

1、创建页面并编写HTML

上传文档:

上传图片:

2、引用AjaxUpload.js文件

3、编写JS脚本

4、创建/Common/UploadHandler.ashx处理程序

<%@ WebHandler Language="C#" Class="UploadHandler" %> 
 
using System; 
using System.Web; 
using System.Text.RegularExpressions; 
using System.IO; 
 
public class UploadHandler : IHttpHandler { 
 private string _filedir = ""; //文件目录 
 /// 
 
 /// 处理上传文件(1:文件格式不正确、2:文件大小不正确、3:上传失败、文件名称:上传成功) 
 /// 
 
 ///  
 public void ProcessRequest (HttpContext context) { 
 _filedir = context.Server.MapPath(@"/file/temp/"); 
 try 
 { 
 string result = "3"; 
 string fileType = context.Request.QueryString["fileType"]; //获取上传文件类型 
 if (fileType == "file") 
 { 
 result = UploadFile(context); //文档上传 
 } 
 else if (fileType == "img") 
 { 
 result = UploadImg(context); //图片上传 
 } 
 context.Response.Write(result); 
 } 
 catch 
 { 
 context.Response.Write("3");//3文件上传失败 
 } 
 } 
 
 /// 
 
 /// 文档上传 
 /// 
 
 ///  
 ///  
 private string UploadFile(HttpContext context) 
 { 
 int cout = context.Request.Files.Count; 
 if (cout > 0) 
 { 
 HttpPostedFile hpf = context.Request.Files[0]; 
 if (hpf != null) 
 { 
 string fileExt = Path.GetExtension(hpf.FileName).ToLower(); 
 //只能上传文件，过滤不可上传的文件类型 
 string fileFilt = ".rar|.zip|.pdf|.pdfx|.txt|.csv|.xls|.xlsx|.doc|.docx......"; 
 if (fileFilt.IndexOf(fileExt) <= -1) 
 { 
 return "1"; 
 } 
 
 //判断文件大小 
 int length = hpf.ContentLength; 
 if (length > 2097152) 
 { 
 return "2"; 
 } 
 
 Random rd = new Random(); 
 DateTime nowTime = DateTime.Now; 
 string newFileName = nowTime.Year.ToString() + nowTime.Month.ToString() + nowTime.Day.ToString() + nowTime.Hour.ToString() + nowTime.Minute.ToString() + nowTime.Second.ToString() + rd.Next(1000, 1000000) + Path.GetExtension(hpf.FileName); 
 if (!Directory.Exists(_filedir)) 
 { 
 Directory.CreateDirectory(_filedir); 
 } 
 string fileName = _filedir + newFileName; 
 hpf.SaveAs(fileName); 
 return newFileName; 
 } 
 
 } 
 return "3"; 
 } 
 
 /// 
 
 /// 图片上传 
 /// 
 
 ///  
 ///  
 private string UploadImg(HttpContext context) 
 { 
 int cout = context.Request.Files.Count; 
 if (cout > 0) 
 { 
 HttpPostedFile hpf = context.Request.Files[0]; 
 if (hpf != null) 
 { 
 string fileExt = Path.GetExtension(hpf.FileName).ToLower(); 
 //只能上传文件，过滤不可上传的文件类型 
 string fileFilt = ".gif|.jpg|.php|.jsp|.jpeg|.png|......"; 
 if (fileFilt.IndexOf(fileExt) <= -1) 
 { 
 return "1"; 
 } 
 
 //判断文件大小 
 int length = hpf.ContentLength; 
 if (length > 204800) 
 { 
 return "2"; 
 } 
 
 Random rd = new Random(); 
 DateTime nowTime = DateTime.Now; 
 string newFileName = nowTime.Year.ToString() + nowTime.Month.ToString() + nowTime.Day.ToString() + nowTime.Hour.ToString() + nowTime.Minute.ToString() + nowTime.Second.ToString() + rd.Next(1000, 1000000) + Path.GetExtension(hpf.FileName); 
 if (!Directory.Exists(_filedir)) 
 { 
 Directory.CreateDirectory(_filedir); 
 } 
 string fileName = _filedir + newFileName; 
 hpf.SaveAs(fileName); 
 return newFileName; 
 } 
 
 } 
 return "3"; 
 } 
 
 #region IHttpHandler 成员 
 
 public bool IsReusable 
 { 
 get { throw new NotImplementedException(); } 
 } 
 
 #endregion 
} 

附件1：页面CSS样式

/*上传文件*/ 
.uploadFile{margin-bottom:10px;} 
/*上传图片*/ 
.uploadImg{} 
.uploadImg img{width:102px; height:px; border:1px solid #CCCCCC; display: block;} 

附件2：AjaxUpload.js文件