jquery插件ajaxupload实现文件上传操作

本文实例讲述了jquery插件ajaxupload实现文件上传操作代码。分享给大家供大家参考。具体如下：
运行效果截图如下：

图1 文件上传前

图2 文件上传后

具体代码如下：

1、创建页面并编写HTML

上传文档:

<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> 

上传图片:

<div class="uploadImg">
 <img id="imgShow" src="/images/nophoto.gif" />
 <input type="hidden" id="hidImgName" />
 <input type="button" id="btnUploadImg" value="上传" />
 <input type="button" id="btnDeleteImg" value="删除" />
</div>

2、引用AjaxUpload.js文件

<script src="/js/common/AjaxUpload.js" type="text/javascript"></script>

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) ? '/Common/UploadHandler.ashx?fileType=file' : action),
  data: {},
  name: 'myfile',
  onSubmit: function(file, ext) {
   if (!(ext && /^(rar|zip|pdf|pdfx|txt|csv|xls|xlsx|doc|docx|RAR|ZIP|PDF|PDFX|TXT|CSV|XLS|XLSX|DOC|DOCX)$/.test(ext))) {
    alert("您上传的文档格式不对，请重新选择！");
    return false;
   }
  },
  onComplete: function(file, response) {
   flagValue = response;
   if (flagValue == "1") {
    alert("您上传的文档格式不对，请重新选择！");
   }
   else if (flagValue == "2") {
    alert("您上传的文档大于2M，请重新选择！");
   }
   else if (flagValue == "3") {
    alert("文档上传失败！");
   }
   else {
    hidPut.value = response;
    doc.innerHTML="<a href='" + g_AjxTempDir + response + "' target='_blank'>" + response + "</a>";
   }
  }
 });
}
//图片上传
function g_AjxUploadImg(btn, img, hidPut) {
 var button = btn, interval;
 new AjaxUpload(button, {
  action: '/Common/UploadHandler.ashx?fileType=img',
  data: {},
  name: 'myfile',
  onSubmit: function(file, ext) {
   if (!(ext && /^(jpg|JPG|png|PNG|gif|GIF)$/.test(ext))) {
    alert("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('.')) ? file.replace(/.*[.]/, '') : '';
 } 

 function hasClass(el, name) {
  var re = new RegExp('\\b' + name + '\\b');
  return re.test(el.className);
 } 

 function addClass(el, name) {
  if (!hasClass(el, name)) {
   el.className += ' ' + name;
  }
 } 

 function removeClass(el, name) {
  var re = new RegExp('\\b' + name + '\\b');
  el.className = el.className.replace(re, '');
 } 

 function removeNode(el) {
  el.parentNode.removeChild(el);
 } 

 /**
  * Easy styling and uploading
  * @constructor
  * @param button An element you want convert to
  * upload button. Tested dimentions up to 500x500px
  * @param {Object} options See defaults below.
  */
 window.AjaxUpload = function (button, options) {
  this._settings = {
   // Location of the server-side upload script
   action: 'upload.php',
   // File upload name
   name: 'userfile',
   // Additional data to send
   data: {},
   // Submit file as soon as it's selected
   autoSubmit: true,
   // The type of data that you're expecting back from the server.
   // html and xml are detected automatically.
   // Only useful when you are using json data as a response.
   // Set to "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="javascript:false;" name="' + id + '" />');
   // src="javascript:false; was added
   // because it possibly removes ie6 prompt
   // "This page contains both secure and nonsecure items"
   // Anyway, it doesn't do any harm.
   iframe.setAttribute('id', id); 

   iframe.style.display = 'none';
   document.body.appendChild(iframe); 

   return iframe;
  },
  /**
   * Creates form, that will be submitted to iframe
   * @param {Element} iframe Where to submit
   * @return {Element} form
   */
  _createForm: function (iframe) {
   var settings = this._settings; 

   // We can't use the following code in IE6
   // var form = document.createElement('form');
   // form.setAttribute('method', 'post');
   // form.setAttribute('enctype', 'multipart/form-data');
   // Because in this case file won't be attached to request
   var form = toElement('<form method="post" enctype="multipart/form-data"></form>'); 

   form.setAttribute('action', settings.action);
   form.setAttribute('target', iframe.name);
   form.style.display = 'none';
   document.body.appendChild(form); 

   // Create hidden input element for each data key
   for (var prop in settings.data) {
    if (settings.data.hasOwnProperty(prop)) {
     var el = document.createElement("input");
     el.setAttribute('type', 'hidden');
     el.setAttribute('name', prop);
     el.setAttribute('value', settings.data[prop]);
     form.appendChild(el);
    }
   }
   return form;
  },
  /**
   * Gets response from iframe and fires onComplete event when ready
   * @param iframe
   * @param file Filename to use in onComplete callback
   */
  _getResponse: function (iframe, file) {
   // getting response
   var toDeleteFlag = false,
    self = this,
    settings = this._settings; 

   addEvent(iframe, 'load', function () { 

    if ( // For Safari
    iframe.src == "javascript:'%3Chtml%3E%3C/html%3E';" ||
    // For FF, IE
    iframe.src == "javascript:'<html></html>';") {
     // First time around, do not delete.
     // We reload to blank page, so that reloading main page
     // does not re-submit the post. 

     if (toDeleteFlag) {
      // Fix busy state in FF3
      setTimeout(function () {
       removeNode(iframe);
      },
      0);
     } 

     return;
    } 

    var doc = iframe.contentDocument ? iframe.contentDocument : window.frames[iframe.id].document; 

    // fixing Opera 9.26,10.00
    if (doc.readyState && doc.readyState != 'complete') {
     // Opera fires load event multiple times
     // Even when the DOM is not ready yet
     // this fix should not affect other browsers
     return;
    } 

    // fixing Opera 9.64
    if (doc.body && doc.body.innerHTML == "false") {
     // In Opera 9.64 event was fired second time
     // when body.innerHTML changed from false
     // to server response approx. after 1 sec
     return;
    } 

    var response; 

    if (doc.XMLDocument) {
     // response is a xml document Internet Explorer property
     response = doc.XMLDocument;
    } else if (doc.body) {
     // response is html document or plain text
     response = doc.body.innerHTML; 

     if (settings.responseType && settings.responseType.toLowerCase() == 'json') {
      // If the document was sent as 'application/javascript' or
      // 'text/javascript', then the browser wraps the text in a <pre>
      // tag and performs html encoding on the contents. In this case,
      // we need to pull the original text content from the text node's
      // nodeValue property to retrieve the unmangled content.
      // Note that IE6 only understands text/html
      if (doc.body.firstChild && doc.body.firstChild.nodeName.toUpperCase() == 'PRE') {
       response = doc.body.firstChild.firstChild.nodeValue;
      } 

      if (response) {
       response = eval("(" + response + ")");
      } else {
       response = {};
      }
     }
    } else {
     // response is a xml document
     response = doc;
    } 

    settings.onComplete.call(self, file, response); 

    // Reload blank page, so that reloading main page
    // does not re-submit the post. Also, remember to
    // delete the frame
    toDeleteFlag = true; 

    // Fix IE mixed content issue
    iframe.src = "javascript:'<html></html>';";
   });
  },
  /**
   * Upload file contained in this._input
   */
  submit: function () {
   var self = this,
    settings = this._settings; 

   if (!this._input || this._input.value === '') {
    return;
   } 

   var file = fileFromPath(this._input.value); 

   // user returned false to cancel upload
   if (false === settings.onSubmit.call(this, file, getExt(file))) {
    this._clearInput();
    return;
   } 

   // sending request
   var iframe = this._createIframe();
   var form = this._createForm(iframe); 

   // assuming following structure
   // div -> input type='file'
   removeNode(this._input.parentNode);
   removeClass(self._button, self._settings.hoverClass); 

   form.appendChild(this._input); 

   form.submit(); 

   // request set, clean up
   removeNode(form);
   form = null;
   removeNode(this._input);
   this._input = null; 

   // Get response from iframe and fire onComplete event when ready
   this._getResponse(iframe, file); 

   // get ready for next request
   this._createInput();
  }
 };
})();

更多精彩内容请参考专题《ajax上传技术汇总》，《javascript文件上传操作汇总》和《jQuery上传操作汇总》进行学习。

以上就是ajaxupload实现文件上传操作的详细代码，希望对大家的学习有所帮助。