ajax图片上传(asp.net +jquery+ashx)

「爱情、让人受尽委屈。」 2022-06-18 03:10 219阅读 0赞

**一、建立Default.aspx页面**

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>
    
    <!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>ajax图片上传</title>
        <script src="js/jquery-1.3.2.min.js" type="text/javascript"></script>
        <script src="js/jquery.form.js" type="text/javascript"></script>
        
        <script type="text/javascript">      
          function upload(){
            var path = document.getElementById("File1").value;
            var img = document.getElementById("img1");
            if($.trim(path)==""){
                alert("请选择要上传的文件");
                return;
                }
                
            $("#form1").ajaxSubmit({
                success: function (str) { 
                    if(str!=null && str!="undefined"){
                        if (str == "1") {alert("上传成功");document.getElementById("img1").src="images/logo.jpg?"+new Date();/*上传后刷新图片*/}
                        else if(str=="2"){alert("只能上传jpg格式的图片");}
                        else if(str=="3"){alert("图片不能大于1M");}
                        else if(str=="4"){alert("请选择要上传的文件");}
                        else {alert('操作失败！');}
                    }
                    else alert('操作失败！');
                },
                error: function (error) {alert(error);},
                url:'Handler.ashx', /*设置post提交到的页面*/
                type: "post", /*设置表单以post方法提交*/
                dataType: "text" /*设置返回值类型为文本*/
            });
        }      
        </script>
    </head>
    <body>
        <form id="form1" runat="server">
            <input id="File1" name="File1" type="file" />
            <input id="iptUp" type="button" value="上传Logo"  οnclick="upload()"/>
            <img id="img1" alt="网站Logo" src="images/weblogo.jpg" />
        </form>
    </body>
    </html>

**二、新建一个一般处理文件Handler.ashx**

<%@ WebHandler Language="C#" Class="Handler" %>
    
    using System;
    using System.Web;
    
    public class Handler : IHttpHandler {
        
        public void ProcessRequest (HttpContext context) {
            HttpPostedFile _upfile = context.Request.Files["File1"];
            if (_upfile == null)
            {
                ResponseWriteEnd(context, "4");//请选择要上传的文件
            }
            else
            {
                string fileName = _upfile.FileName;/*获取文件名： C:\Documents and Settings\Administrator\桌面\123.jpg*/
                string suffix = fileName.Substring(fileName.LastIndexOf(".") + 1).ToLower();/*获取后缀名并转为小写： jpg*/
                int bytes = _upfile.ContentLength;//获取文件的字节大小
    
                if (suffix != "jpg")
                    ResponseWriteEnd(context, "2"); //只能上传JPG格式图片
                if (bytes > 1024 * 1024)
                    ResponseWriteEnd(context, "3"); //图片不能大于1M
    
                _upfile.SaveAs(HttpContext.Current.Server.MapPath("~/images/logo.jpg"));//保存图片
                ResponseWriteEnd(context, "1"); //上传成功
            }
        }
    
        private void ResponseWriteEnd(HttpContext context, string msg)
        {
            context.Response.Write(msg);
            context.Response.End();
        }
        
        public bool IsReusable {
            get {
                return false;
            }
        }
    }

> **项目结构图  
> ![0_1316619385VAT7.gif][]**

![0_131661978147Ks.gif][]

[0_1316619385VAT7.gif]: /images/20220618/486a817d2aa34eac88eda416ba04ab9c.png
[0_131661978147Ks.gif]: /images/20220618/45ced50cef4e45bd98b56ddb9bda6bb1.png