网页中这样：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1">
</head>
<title></title>
<script src="Scripts/jquery-1.8.2.min.js"></script>
<script type="text/javascript">
function uploadImage() {
//判断是否有选择上传文件
var imgPath = $("#uploadFile").val();
if (imgPath == "") {
alert("请选择上传图片！");
return;
}
//判断上传文件的后缀名
var strExtension = imgPath.substr(imgPath.lastIndexOf(‘.‘) + 1);
if (strExtension != ‘jpg‘ && strExtension != ‘gif‘
&& strExtension != ‘png‘ && strExtension != ‘bmp‘) {
alert("请选择图片文件");
return;
}
$.ajax({
type: "POST",
url: "handler/UploadImageHandler.ashx",
data: { imgPath: $("#uploadFile").val() },
cache: false,
success: function (data) {
alert("上传成功");
$("#imgDiv").empty();
$("#imgDiv").html(data);
$("#imgDiv").show();
},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert("上传失败，请检查网络后重试");
}
});
}
</script>
<body>
<form enctype="multipart/form-data" method="post">
<input type="file" id="uploadFile" />
<input type="button" id="btnUpload" value="确定" onclick="uploadImage()" />
<div id="imgDiv">
</div>
</form>
</body>
</html>
一般处理程序中这样：
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Web;
namespace test
{
/// <summary>
/// UploadImageHandler 的摘要说明
/// </summary>
public class UploadImageHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
//不知道为什么获取不到
//HttpPostedFile file = context.Request.Files["userFile"];
string filePath = context.Request["imgPath"];
string path = "UploadImgs\\";
Bitmap map = new Bitmap(filePath);
string fileName = Path.GetFileName(filePath);
string mapPath = context.Server.MapPath("~");
string savePath = mapPath + "\\" + path + fileName;
map.Save(savePath);
//上传成功后显示IMG文件
StringBuilder sb = new StringBuilder();
sb.Append("<img id=\"imgUpload\" src=\"" + path.Replace("\\", "/") + fileName + "\" />");
context.Response.Write(sb.ToString());
context.Response.End();
}
public bool IsReusable
{
get
{
return false;
}
}
}
}
原文：http://www.cnblogs.com/haofaner/p/5855425.html