<div class="uploadFile"> 
 <span id="doc"><input type="text" disabled="disabled" /></span> 
 <input type="hidden" id="hidFileName" /> 
 <input type="button" id="btnUploadFile" value="上传" /> 
 <input type="button" id="btnDeleteFile" value="删除" /> 
</div> 

<div class="uploadImg"> 
 <img id="imgShow" src="/UploadFiles/2021-04-02/nophoto.gif">

2、引用AjaxUpload.js文件




<script src="/UploadFiles/2021-04-02/AjaxUpload.js">

3、编写JS脚本




window.onload = function() { 
 init(); //初始化 
} 
 
//初始化 
function init() { 
 //初始化文档上传 
 var btnFile = document.getElementById("btnUploadFile"); 
 var doc = document.getElementById("doc"); 
 var hidFileName = document.getElementById("hidFileName"); 
 document.getElementById("btnDeleteFile").onclick = function() { DelFile(doc, hidFileName); }; 
 g_AjxUploadFile(btnFile, doc, hidFileName); 
 
 //初始化图片上传 
 var btnImg = document.getElementById("btnUploadImg"); 
 var img = document.getElementById("imgShow"); 
 var hidImgName = document.getElementById("hidImgName"); 
 document.getElementById("btnDeleteImg").onclick = function() { DelImg(img, hidImgName); }; 
 g_AjxUploadImg(btnImg, img, hidImgName); 
} 
 
 
var g_AjxTempDir = "/file/temp/"; 
//文档上传 
function g_AjxUploadFile(btn, doc, hidPut, action) { 
 var button = btn, interval; 
 new AjaxUpload(button, { 
 action: ((action == null || action == undefined) "您上传的文档格式不对，请重新选择！"); 
 return false; 
 } 
 }, 
 onComplete: function(file, response) { 
 flagValue = response; 
 if (flagValue == "1") { 
 alert("您上传的文档格式不对，请重新选择！"); 
 } 
 else if (flagValue == "2") { 
 alert("您上传的文档大于2M，请重新选择！"); 
 } 
 else if (flagValue == "3") { 
 alert("文档上传失败！"); 
 } 
 else { 
 hidPut.value = response; 
 doc.innerHTML="<a href='" + g_AjxTempDir + response + "' target='_blank'>" + response + "</a>"; 
 } 
 } 
 }); 
} 
//图片上传 
function g_AjxUploadImg(btn, img, hidPut) { 
 var button = btn, interval; 
 new AjaxUpload(button, { 
 action: '/Common/UploadHandler.ashx"您上传的图片格式不对，请重新选择！"); 
 return false; 
 } 
 }, 
 onComplete: function(file, response) { 
 flagValue = response; 
 if (flagValue == "1") { 
 alert("您上传的图片格式不对，请重新选择！"); 
 } 
 else if (flagValue == "2") { 
 alert("您上传的图片大于200K，请重新选择！"); 
 } 
 else if (flagValue == "3") { 
 alert("图片上传失败！"); 
 } 
 else { 
 hidPut.value = response; 
 img.src = g_AjxTempDir + response; 
 } 
 } 
 }); 
} 
 
//删除文档 
function DelFile(doc, hidPut) { 
 hidPut.value = ""; 
 doc.innerHTML = "<input type=\"text\" disabled=\"disabled\" />"; 
} 
 
//删除图片 
function DelImg(img, hidPut) { 
 hidPut.value = ""; 
 img.src = "/images/nophoto.gif"; 
} 



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 
 /// <summary> 
 /// 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) 
 /// </summary> 
 /// <param name="context"></param> 
 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 
 } 
 } 
 
 /// <summary> 
 /// 文档上传 
 /// </summary> 
 /// <param name="context"></param> 
 /// <returns></returns> 
 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"; 
 } 
 
 /// <summary> 
 /// 图片上传 
 /// </summary> 
 /// <param name="context"></param> 
 /// <returns></returns> 
 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:64px; border:1px solid #CCCCCC; display: block;} 



附件2：AjaxUpload.js文件




/** 
 * AJAX Upload ( http://valums.com/ajax-upload/ ) 
 * Copyright (c) Andris Valums 
 * Licensed under the MIT license ( http://valums.com/mit-license/ ) 
 * Thanks to Gary Haran, David Mark, Corey Burns and others for contributions 
 */ 
(function () { 
 /* global window */ 
 /* jslint browser: true, devel: true, undef: true, nomen: true, bitwise: true, regexp: true, newcap: true, immed: true */ 
 
 /** 
 * Wrapper for FireBug's console.log 
 */ 
 
 function log() { 
 if (typeof(console) != 'undefined' && typeof(console.log) == 'function') { 
 Array.prototype.unshift.call(arguments, '[Ajax Upload]'); 
 console.log(Array.prototype.join.call(arguments, ' ')); 
 } 
 } 
 
 /** 
 * Attaches event to a dom element. 
 * @param {Element} el 
 * @param type event name 
 * @param fn callback This refers to the passed element 
 */ 
 
 function addEvent(el, type, fn) { 
 if (el.addEventListener) { 
 el.addEventListener(type, fn, false); 
 } else if (el.attachEvent) { 
 el.attachEvent('on' + type, function () { 
 fn.call(el); 
 }); 
 } else { 
 throw new Error('not supported or DOM not loaded'); 
 } 
 } 
 
 /** 
 * Attaches resize event to a window, limiting 
 * number of event fired. Fires only when encounteres 
 * delay of 100 after series of events. 
 * 
 * Some browsers fire event multiple times when resizing 
 * http://www.quirksmode.org/dom/events/resize.html 
 * 
 * @param fn callback This refers to the passed element 
 */ 
 
 function addResizeEvent(fn) { 
 var timeout; 
 
 addEvent(window, 'resize', function () { 
 if (timeout) { 
 clearTimeout(timeout); 
 } 
 timeout = setTimeout(fn, 100); 
 }); 
 } 
 
 // Needs more testing, will be rewriten for next version 
 // getOffset function copied from jQuery lib (http://jquery.com/) 
 if (document.documentElement.getBoundingClientRect) { 
 // Get Offset using getBoundingClientRect 
 // http://ejohn.org/blog/getboundingclientrect-is-awesome/ 
 var getOffset = function (el) { 
 var box = el.getBoundingClientRect(); 
 var doc = el.ownerDocument; 
 var body = doc.body; 
 var docElem = doc.documentElement; // for ie 
 var clientTop = docElem.clientTop || body.clientTop || 0; 
 var clientLeft = docElem.clientLeft || body.clientLeft || 0; 
 
 // In Internet Explorer 7 getBoundingClientRect property is treated as physical, 
 // while others are logical. Make all logical, like in IE8. 
 var zoom = 1; 
 if (body.getBoundingClientRect) { 
 var bound = body.getBoundingClientRect(); 
 zoom = (bound.right - bound.left) / body.clientWidth; 
 } 
 
 if (zoom > 1) { 
 clientTop = 0; 
 clientLeft = 0; 
 } 
 
 var top = box.top / zoom + (window.pageYOffset || docElem && docElem.scrollTop / zoom || body.scrollTop / zoom) - clientTop, 
 left = box.left / zoom + (window.pageXOffset || docElem && docElem.scrollLeft / zoom || body.scrollLeft / zoom) - clientLeft; 
 
 return { 
 top: top, 
 left: left 
 }; 
 }; 
 } else { 
 // Get offset adding all offsets 
 var getOffset = function (el) { 
 var top = 0, 
 left = 0; 
 do { 
 top += el.offsetTop || 0; 
 left += el.offsetLeft || 0; 
 el = el.offsetParent; 
 } while (el); 
 
 return { 
 left: left, 
 top: top 
 }; 
 }; 
 } 
 
 /** 
 * Returns left, top, right and bottom properties describing the border-box, 
 * in pixels, with the top-left relative to the body 
 * @param {Element} el 
 * @return {Object} Contains left, top, right,bottom 
 */ 
 
 function getBox(el) { 
 var left, right, top, bottom; 
 var offset = getOffset(el); 
 left = offset.left; 
 top = offset.top; 
 
 right = left + el.offsetWidth; 
 bottom = top + el.offsetHeight; 
 
 return { 
 left: left, 
 right: right, 
 top: top, 
 bottom: bottom 
 }; 
 } 
 
 /** 
 * Helper that takes object literal 
 * and add all properties to element.style 
 * @param {Element} el 
 * @param {Object} styles 
 */ 
 
 function addStyles(el, styles) { 
 for (var name in styles) { 
 if (styles.hasOwnProperty(name)) { 
 el.style[name] = styles[name]; 
 } 
 } 
 } 
 
 /** 
 * Function places an absolutely positioned 
 * element on top of the specified element 
 * copying position and dimentions. 
 * @param {Element} from 
 * @param {Element} to 
 */ 
 
 function copyLayout(from, to) { 
 var box = getBox(from); 
 
 addStyles(to, { 
 position: 'absolute', 
 left: box.left + 'px', 
 top: box.top + 'px', 
 width: from.offsetWidth + 'px', 
 height: from.offsetHeight + 'px' 
 }); 
 } 
 
 /** 
 * Creates and returns element from html chunk 
 * Uses innerHTML to create an element 
 */ 
 var toElement = (function () { 
 var div = document.createElement('div'); 
 return function (html) { 
 div.innerHTML = html; 
 var el = div.firstChild; 
 return div.removeChild(el); 
 }; 
 })(); 
 
 /** 
 * Function generates unique id 
 * @return unique id 
 */ 
 var getUID = (function () { 
 var id = 0; 
 return function () { 
 return 'ValumsAjaxUpload' + id++; 
 }; 
 })(); 
 
 /** 
 * Get file name from path 
 * @param {String} file path to file 
 * @return filename 
 */ 
 
 function fileFromPath(file) { 
 return file.replace(/.*(\/|\\)/, ""); 
 } 
 
 /** 
 * Get file extension lowercase 
 * @param {String} file name 
 * @return file extenstion 
 */ 
 
 function getExt(file) { 
 return (-1 !== file.indexOf('.')) "json" in that case. 
 responseType: false, 
 // Class applied to button when mouse is hovered 
 hoverClass: 'hover', 
 // Class applied to button when AU is disabled 
 disabledClass: 'disabled', 
 // When user selects a file, useful with autoSubmit disabled 
 // You can return false to cancel upload 
 onChange: function (file, extension) {}, 
 // Callback to fire before file is uploaded 
 // You can return false to cancel upload 
 onSubmit: function (file, extension) {}, 
 // Fired when file upload is completed 
 // WARNING! DO NOT USE "FALSE" STRING AS A RESPONSE! 
 onComplete: function (file, response) {} 
 }; 
 
 // Merge the users options with our defaults 
 for (var i in options) { 
 if (options.hasOwnProperty(i)) { 
 this._settings[i] = options[i]; 
 } 
 } 
 
 // button isn't necessary a dom element 
 if (button.jquery) { 
 // jQuery object was passed 
 button = button[0]; 
 } else if (typeof button == "string") { 
 if (/^#.*/.test(button)) { 
 // If jQuery user passes #elementId don't break it  
 button = button.slice(1); 
 } 
 
 button = document.getElementById(button); 
 } 
 
 if (!button || button.nodeType !== 1) { 
 throw new Error("Please make sure that you're passing a valid element"); 
 } 
 
 if (button.nodeName.toUpperCase() == 'A') { 
 // disable link  
 addEvent(button, 'click', function (e) { 
 if (e && e.preventDefault) { 
  e.preventDefault(); 
 } else if (window.event) { 
  window.event.returnValue = false; 
 } 
 }); 
 } 
 
 // DOM element 
 this._button = button; 
 // DOM element  
 this._input = null; 
 // If disabled clicking on button won't do anything 
 this._disabled = false; 
 
 // if the button was disabled before refresh if will remain 
 // disabled in FireFox, let's fix it 
 this.enable(); 
 
 this._rerouteClicks(); 
 }; 
 
 // assigning methods to our class 
 AjaxUpload.prototype = { 
 setData: function (data) { 
 this._settings.data = data; 
 }, 
 disable: function () { 
 addClass(this._button, this._settings.disabledClass); 
 this._disabled = true; 
 
 var nodeName = this._button.nodeName.toUpperCase(); 
 if (nodeName == 'INPUT' || nodeName == 'BUTTON') { 
 this._button.setAttribute('disabled', 'disabled'); 
 } 
 
 // hide input 
 if (this._input) { 
 // We use visibility instead of display to fix problem with Safari 4 
 // The problem is that the value of input doesn't change if it 
 // has display none when user selects a file 
 this._input.parentNode.style.visibility = 'hidden'; 
 } 
 }, 
 enable: function () { 
 removeClass(this._button, this._settings.disabledClass); 
 this._button.removeAttribute('disabled'); 
 this._disabled = false; 
 
 }, 
 /** 
 * Creates invisible file input 
 * that will hover above the button 
 * <div><input type='file' /></div> 
 */ 
 _createInput: function () { 
 var self = this; 
 
 var input = document.createElement("input"); 
 input.setAttribute('type', 'file'); 
 input.setAttribute('name', this._settings.name); 
 
 addStyles(input, { 
 'position': 'absolute', 
 // in Opera only 'browse' button 
 // is clickable and it is located at 
 // the right side of the input 
 'right': 0, 
 'margin': 0, 
 'padding': 0, 
 'fontSize': '480px', 
 'cursor': 'pointer' 
 }); 
 
 var div = document.createElement("div"); 
 addStyles(div, { 
 'display': 'block', 
 'position': 'absolute', 
 'overflow': 'hidden', 
 'margin': 0, 
 'padding': 0, 
 'opacity': 0, 
 // Make sure browse button is in the right side 
 // in Internet Explorer 
 'direction': 'ltr', 
 //Max zIndex supported by Opera 9.0-9.2 
 'zIndex': 2147483583 
 }); 
 
 // Make sure that element opacity exists. 
 // Otherwise use IE filter 
 if (div.style.opacity !== "0") { 
 if (typeof(div.filters) == 'undefined') { 
  throw new Error('Opacity not supported by the browser'); 
 } 
 div.style.filter = "alpha(opacity=0)"; 
 } 
 
 addEvent(input, 'change', function () { 
 
 if (!input || input.value === '') { 
  return; 
 } 
 
 // Get filename from input, required  
 // as some browsers have path instead of it 
 var file = fileFromPath(input.value); 
 
 if (false === self._settings.onChange.call(self, file, getExt(file))) { 
  self._clearInput(); 
  return; 
 } 
 
 // Submit form when value is changed 
 if (self._settings.autoSubmit) { 
  self.submit(); 
 } 
 }); 
 
 addEvent(input, 'mouseover', function () { 
 addClass(self._button, self._settings.hoverClass); 
 }); 
 
 addEvent(input, 'mouseout', function () { 
 removeClass(self._button, self._settings.hoverClass); 
 
 // We use visibility instead of display to fix problem with Safari 4 
 // The problem is that the value of input doesn't change if it 
 // has display none when user selects a file 
 input.parentNode.style.visibility = 'hidden'; 
 
 }); 
 
 div.appendChild(input); 
 document.body.appendChild(div); 
 
 this._input = input; 
 }, 
 _clearInput: function () { 
 if (!this._input) { 
 return; 
 } 
 
 // this._input.value = ''; Doesn't work in IE6   
 removeNode(this._input.parentNode); 
 this._input = null; 
 this._createInput(); 
 
 removeClass(this._button, this._settings.hoverClass); 
 }, 
 /** 
 * Function makes sure that when user clicks upload button, 
 * the this._input is clicked instead 
 */ 
 _rerouteClicks: function () { 
 var self = this; 
 
 // IE will later display 'access denied' error 
 // if you use using self._input.click() 
 // other browsers just ignore click() 
 
 addEvent(self._button, 'mouseover', function () { 
 if (self._disabled) { 
  return; 
 } 
 
 if (!self._input) { 
  self._createInput(); 
 } 
 
 var div = self._input.parentNode; 
 copyLayout(self._button, div); 
 div.style.visibility = 'visible'; 
 
 }); 
 
 
 // commented because we now hide input on mouseleave 
 /** 
 * When the window is resized the elements 
 * can be misaligned if button position depends 
 * on window size 
 */ 
 //addResizeEvent(function(){ 
 // if (self._input){ 
 // copyLayout(self._button, self._input.parentNode); 
 // } 
 //}); 
 
 }, 
 /** 
 * Creates iframe with unique name 
 * @return {Element} iframe 
 */ 
 _createIframe: function () { 
 // We can't use getTime, because it sometimes return 
 // same value in safari :( 
 var id = getUID(); 
 
 // We can't use following code as the name attribute 
 // won't be properly registered in IE6, and new window 
 // on form submit will open 
 // var iframe = document.createElement('iframe'); 
 // iframe.setAttribute('name', id);  
 
 var iframe = toElement('<iframe src="/UploadFiles/2021-04-02/javascript:false;">

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。

                                
                                

                                    AjaxUpLoad.js,文件上传