ajaxfileupload.js是上传文件的一个插件,最近碰到的一个问题是在谷歌浏览器上传文件之后,原文本框中的文件名称消失,网上搜了好长时间也没有十分满意的答案。无刷新上传文件我想到的只有ajax,ajaxfileupload.js插件非常简单,看个简单例子就会使用,不用明白js里面写的到底是什么。流程就是就是先利用jQuery的选择器获得file文件上传框中的文件路径值,然后js就会动态的创建一个iframe和表单,并在里面建立一个新的file 文件框,提供post方式提交到后台。最后,返回结果到前台。
我的功能需求是在选中图片的时候就自动上传图片,并且可以马上显示,刚做的时候没有想到上传图片,用了一个onchange函数可以让上传的图片显示出来,之后提交之前有一个预览功能,之前的上传的图片还要展现出来,这个时候才想起来把图片先存放某一个地方,这样连上传即展现的功能也能解决。不过为了以后会用到这个功能我就和上传图片的一起写出来。
html上传文件的
1 <script type="text/javascript" src='/Public/js/jquery-1.4.2.min.js'></script> 2 <!--上传图片的JS 修改之后的--> 3 <script charset="utf-8" src="/Public/js/ajaxfileupload_modify.js"></script> 4 <script type="text/javascript"> 5 //图片展示和删除 其他函数是选中图片下面就会展现出来图片的相关函数 6 function onUploadImgChange(sender,img,obj){ 7 if( !sender.value.match( /.jpg|.gif|.png|.bmp|.jpeg/i ) ){ 8 alert('图片格式无效!'); 9 return false; 10 } 11 var objPreview = document.getElementById(obj); 12 var file=document.getElementById(img); 13 if( sender.files && sender.files[0] ){ 14 objPreview.style.display = 'block'; 15 objPreview.style.width = 'auto'; 16 objPreview.style.height = 'auto'; 17 objPreview.src = window.URL.createObjectURL(file.files[0]); 18 } 19 //上传到服务器图片方便预览 这一块是选中图片即上传 20 $.ajaxFileUpload ({ 21 url:'__URL__/page_preview', //你处理上传文件的服务端 22 secureuri:false, //与页面处理代码中file相对应的ID值 23 fileElementId:'btn_pic', 24 dataType: 'json', //返回数据类型:text,xml,json,html,scritp,jsonp五种 25 success: function (data) 26 { 27 if(data.file_infor ==1 ) 28 { 29 //存放的地址展示出来 30 $("#tmp_btn_pic").val(data.file_url); 31 } 32 } 33 }) 34 } 35 36 function onPreviewLoad(sender){ 37 autoSizePreview( sender, sender.offsetWidth, sender.offsetHeight ); 38 } 39 40 function autoSizePreview( objPre, originalWidth, originalHeight ){ 41 var zoomParam = clacImgZoomParam( 300, 300, originalWidth, originalHeight ); 42 objPre.style.width = zoomParam.width + 'px'; 43 objPre.style.height = zoomParam.height + 'px'; 44 objPre.style.marginTop = zoomParam.top + 'px'; 45 objPre.style.marginLeft = zoomParam.left + 'px'; 46 } 47 48 function clacImgZoomParam( maxWidth, maxHeight, width, height ){ 49 var param = { width, height:height, top:0, left:0 }; 50 if( width>maxWidth || height>maxHeight ){ 51 rateWidth = width / maxWidth; 52 rateHeight = height / maxHeight; 53 if( rateWidth > rateHeight ){ 54 param.width = maxWidth; 55 param.height = height / rateWidth; 56 }else{ 57 param.width = width / rateHeight; 58 param.height = maxHeight; 59 } 60 } 61 param.left = (maxWidth - param.width) / 2; 62 param.top = (maxHeight - param.height) / 2; 63 return param; 64 } 65 66 function del_img(obj,div){ 67 if(confirm("确定要删除此图片?")) 68 { 69 $('#'+obj+'').val(''); 70 objPreview = document.getElementById(div); 71 objPreview.style.display = 'none'; 72 }else{ 73 return false; 74 } 75 } 76 </script> 77 <input type="file" name="btn_pic" id="btn_pic" onchange="onUploadImgChange(this,'btn_pic','preview2');" /> 78 <div> 79 <img id="preview2" onload="onPreviewLoad(this)"/> 80 </div> 81 <input type="button" value="删除" onclick="del_img('btn_pic','preview2');" />
php后台处理
function page_preview() {//出来ajaxupload的图片 //如果有按钮图片先存放某个地方 $folder = "/img/" . date("Ym/d/"); $this->mkDirs(UPLOAD_PATH . $folder); $path = $folder . time() . rand(1000,9999) . $_FILES['btn_pic']['name']; $img_path = UPLOAD_PATH . $path; $ok=@move_uploaded_file($_FILES['btn_pic']['tmp_name'],$img_path); if($ok === FALSE) { $file_infor = 0; echo '{"file_infor":"' . $file_infor .'"}'; }else { $file_infor = 1; echo '{"file_infor":"' . $file_infor . '","file_url":"' . $path . '"}'; } }
在原来的ajaxfileupload.js中修改了一下就可以传完之后原来的文本框的值不会丢失。这也是从网上搜集来的我总结一下
jQuery.extend({ createUploadIframe: function(id, uri) { //create frame var frameId = 'jUploadFrame' + id; if(window.ActiveXObject) { if(jQuery.browser.version=="9.0" || jQuery.browser.version=="10.0"){ var io = document.createElement('iframe'); io.id = frameId; io.name = frameId; }else if(jQuery.browser.version=="6.0" || jQuery.browser.version=="7.0" || jQuery.browser.version=="8.0"){ var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />'); if(typeof uri== 'boolean'){ io.src = 'javascript:false'; } else if(typeof uri== 'string'){ io.src = uri; } } } else { var io = document.createElement('iframe'); io.id = frameId; io.name = frameId; } io.style.position = 'absolute'; io.style.top = '-1000px'; io.style.left = '-1000px'; document.body.appendChild(io); return io }, createUploadForm: function(id, fileElementId) { //create form var formId = 'jUploadForm' + id; var fileId = 'jUploadFile' + id; var form = $('<form action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>'); var oldElement = $('#' + fileElementId); var newElement = $(oldElement).clone(); $(oldElement).attr('id', fileId); $(oldElement).before(newElement); $(oldElement).appendTo(form); //set attributes $(form).css('position', 'absolute'); $(form).css('top', '-1200px'); $(form).css('left', '-1200px'); $(form).appendTo('body'); return form; }, ajaxFileUpload: function(s) { // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout s = jQuery.extend({}, jQuery.ajaxSettings, s); var id = s.fileElementId; var form = jQuery.createUploadForm(id, s.fileElementId); var io = jQuery.createUploadIframe(id, s.secureuri); var frameId = 'jUploadFrame' + id; var formId = 'jUploadForm' + id; // Watch for a new set of requests if (s.global && ! jQuery.active++) { jQuery.event.trigger("ajaxStart"); } var requestDone = false; // Create the request object var xml = {} if ( s.global ) jQuery.event.trigger("ajaxSend", [xml, s]); // Wait for a response to come back var uploadCallback = function(isTimeout) { var io = document.getElementById(frameId); try { if(io.contentWindow) { xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null; xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document; }else if(io.contentDocument) { xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null; xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document; } }catch(e) { jQuery.handleError(s, xml, null, e); } if ( xml || isTimeout == "timeout") { requestDone = true; var status; try { status = isTimeout != "timeout" ? "success" : "error"; // Make sure that the request was successful or notmodified if ( status != "error" ) { // process the data (runs the xml through httpData regardless of callback) var data = jQuery.uploadHttpData(xml, s.dataType); // If a local callback was specified, fire it and pass it the data if ( s.success ) s.success( data, status ); // Fire the global callback if( s.global ) jQuery.event.trigger("ajaxSuccess", [xml, s]); } else jQuery.handleError(s, xml, status); } catch(e) { status = "error"; jQuery.handleError(s, xml, status, e); } // The request was completed if(s.global) jQuery.event.trigger("ajaxComplete", [xml, s]); // Handle the global AJAX counter if (s.global && ! --jQuery.active) jQuery.event.trigger("ajaxStop"); // Process result if (s.complete) s.complete(xml, status); jQuery(io).unbind(); setTimeout(function() { try { $(io).remove(); //修改的 var fileElementId = 'jUploadFile' + id; var oldElement = $('#' + fileElementId); var newElement = $('#' + id); $(newElement).after(oldElement); $(newElement).remove(); $(oldElement).attr('id', id); //结束 $(form).remove(); } catch(e) { jQuery.handleError(s, xml, null, e); } }, 100) xml = null } } // Timeout checker if (s.timeout > 0) { setTimeout(function(){ // Check to see if the request is still happening if(!requestDone ) uploadCallback("timeout"); }, s.timeout); } try { // var io = $('#' + frameId); var form = $('#' + formId); $(form).attr('action', s.url); $(form).attr('method', 'POST'); $(form).attr('target', frameId); if(form.encoding) { form.encoding = 'multipart/form-data'; } else { form.enctype = 'multipart/form-data'; } $(form).submit(); } catch(e) { jQuery.handleError(s, xml, null, e); } if(window.attachEvent){ document.getElementById(frameId).attachEvent('onload', uploadCallback); } else{ document.getElementById(frameId).addEventListener('load', uploadCallback, false); } return {abort: function () {}}; }, uploadHttpData: function( r, type ) { var data = !type; data = type == "xml" || data ? r.responseXML : r.responseText; // If the type is "script", eval it in global context if (type == "script") jQuery.globalEval( data ); // Get the JavaScript object, if JSON is used. if (type == "json") eval( "data = " + data ); // evaluate scripts within html if (type == "html") jQuery("<div>").html(data).evalScripts(); //alert($('param', data).each(function(){alert($(this).attr('value'));})); return data; } })
这样就解决了ajax上传之后 原本文本框丢失的问题。
图片上传就显示,我们需要了解Javascript里File对象、Blob对象和window.URL.createObjectURL()方法。上面所写的html中已经有了立即显示的代码
以后可以研究研究其中的机制。
所有这些我只是写出来解决的方法,但是具体的原理还不是很懂。欢迎大家吐槽和评论!