自己动手打造ajax图片上传(网上没有的)

 
上传图片 
 
 
 

 
ajax上传 
 
 
 
 
最新修改人员： 
 
 
 

 
 

说明：这种方法目前测试支持IE8/9,谷歌，兼容比方法1好。建议采用方法2

文件上传后台处理代码（asp.net版）

<%@ webhandler Language="C#" class="Upload" %> 

using System; 
using System.Collections; 
using System.Web; 
using System.IO; 
using System.Globalization; 
using LitJson; 
public class Upload : IHttpHandler 
{ 
private HttpContext context; 
public void ProcessRequest(HttpContext context) 
{ 
String aspxUrl = context.Request.Path.Substring(0, context.Request.Path.LastIndexOf("/") + 1); 

//文件保存目录路径 
String savePath = "attached/"; 
//文件保存目录URL 
String saveUrl = aspxUrl + "attached/"; 
//定义允许上传的文件扩展名 
Hashtable extTable = new Hashtable(); 
extTable.Add("image", "gif,jpg,jpeg,png,bmp"); 
extTable.Add("flash", "swf,flv"); 
extTable.Add("media", "swf,flv,mp3,wav,wma,wmv,mid,avi,mpg,asf,rm,rmvb"); 
extTable.Add("file", "doc,docx,xls,xlsx,ppt,htm,html,txt,zip,rar,gz,bz2"); 
//最大文件大小 
int maxSize = 1000000; 
this.context = context; 
HttpPostedFile imgFile = context.Request.Files["imgFile"]; 
if (imgFile == null) 
{ 
showError("请选择文件。"); 
} 
String dirPath = context.Server.MapPath(savePath); 
if (!Directory.Exists(dirPath)) 
{ 
showError("上传目录不存在。"); 
} 
String dirName = context.Request.QueryString["dir"]; 
if (String.IsNullOrEmpty(dirName)) { 
dirName = "image"; 
} 
if (!extTable.ContainsKey(dirName)) { 
showError("目录名不正确。"); 
} 
String fileName = imgFile.FileName; 
String fileExt = Path.GetExtension(fileName).ToLower(); 
if (imgFile.InputStream == null || imgFile.InputStream.Length > maxSize) 
{ 
showError("上传文件大小超过限制。"); 
} 
if (String.IsNullOrEmpty(fileExt) || Array.IndexOf(((String)extTable[dirName]).Split(','), fileExt.Substring(1).ToLower()) == -1) 
{ 
showError("上传文件扩展名是不允许的扩展名。n只允许" + ((String)extTable[dirName]) + "格式。"); 
} 
//创建文件夹 
dirPath += dirName + "/"; 
saveUrl += dirName + "/"; 
if (!Directory.Exists(dirPath)) { 
Directory.CreateDirectory(dirPath); 
} 
String ymd = DateTime.Now.ToString("yyyyMMdd", DateTimeFormatInfo.InvariantInfo); 
dirPath += ymd + "/"; 
saveUrl += ymd + "/"; 
if (!Directory.Exists(dirPath)) { 
Directory.CreateDirectory(dirPath); 
} 
String newFileName = DateTime.Now.ToString("yyyyMMddHHmmss_ffff", DateTimeFormatInfo.InvariantInfo) + fileExt; 
String filePath = dirPath + newFileName; 
imgFile.SaveAs(filePath); 
String fileUrl = saveUrl + newFileName; 
Hashtable hash = new Hashtable(); 
hash["error"] = 0; 
hash["url"] = fileUrl; 
context.Response.AddHeader("Content-Type", "text/html; charset=UTF-8"); 
context.Response.Write(JsonMapper.ToJson(hash)); 
context.Response.End(); 
} 
private void showError(string message) 
{ 
Hashtable hash = new Hashtable(); 
hash["error"] = 1; 
hash["message"] = message; 
context.Response.AddHeader("Content-Type", "text/html; charset=UTF-8"); 
context.Response.Write(JsonMapper.ToJson(hash)); 
context.Response.End(); 
} 
public bool IsReusable 
{ 
get 
{ 
return true; 
} 
} 
}