（一般处理程序）

　　 public void ProcessRequest(HttpContext context)

        {

            context.Response.ContentType = "text/plain";

            string filePath = "";

            string msg = "";

            string fileNewName = "";

            string result = string.Empty; //也是定义一个空变量

            string fileNewPath = string.Empty;

            //接收文件

            HttpFileCollection files = context.Request.Files;

            //判断是否获取到文件

            if (files.Count > 0)

            {

                //设置图片名称

                //DateTime.Now.ToString("yyyyMMddHHmmssff")

                fileNewName = Guid.NewGuid() + "_" + Path.GetFileName(files[0].FileName);

                //保存文件

                files[0].SaveAs(context.Server.MapPath("~/Upload/" + fileNewName));

                msg = "图片上传成功";

                fileNewPath = "Upload/" + fileNewName;

                result = "{msg:'" + msg + "',fileNewPath:'" + fileNewPath + "'}"

               

            }

            else

            {

                msg = "图片上传失败";

                result = "{msg:'" + msg + "'}";

            }

            context.Response.Write(result);

            context.Response.End();

        }

 

 <script type="text/javascript">

        $(function () {

            $(".file").on("change", "input[type='file']", function () {

                var filePath = $(this).val();

                //设置上传文件的类型

                if (filePath.indexOf("xls") != -1 || filePath.indexOf("xlsx") != -1 || filePath.indexOf("jpg") != -1) {

                    alert(111);

                    //执行上传文件的操作

                    $.ajaxFileUpload({

                        url: "UploadHandler.ashx", //   请求地址

                        secureuri: false, // 是否开启安全提交，默认为false

                        fileElementId: "btnfile", //需要上传的文件域的ID 也就是 <input type="file" id="btnfile" name="btnfile" />里面的id

                        dataType: "json", //制定返回数据类型（json,html，xml,script） 如果不写，jquery会自动判断

                        success: function (data) {  //执行成功之后自动执行的函数

                            console.log(data);

                            alert(data.msg);

                            $("#txt_filepath").val(data.fileNewPath);

                            $("#hImg").prop("src", data.fileNewPath);

                        },

                        error: function (data) { //执行失败之后自动执行的函数

                            console.log(data);

                        }

                    })

                }

                else {

                    alert("请选择正确格式的文件");

                }

            })

        })

    </script>

 

 <form id="form1" runat="server">

        <div>

            <span>选择文件：</span>

            <input type="text" readonly="readonly" id="txt_filepath" />

            <a class="file">

                <input type="file" id="btnfile" name="btnfile" />

                浏览文件

            </a>

            <img style="width: 300px; height: 300px;" id="hImg" />

        </div>