今天试了下mvc自带的ajax，发现上传文件时后端action接收不到文件， Request.Files和HttpPostedFileBase都接收不到。。。。。后来搜索了下才知道mvc自带的Ajax不支持文件上传，无奈之下只能用其他的方式
第一种方式：通过 jquery的ajaxSubmit ---》（先引入jQuery脚本）需要引入jquery.form.min.js（可以通过NuGet下载） 直接上代码
@{ ???Layout = null;}<!DOCTYPE html><html><head> ???<meta name="viewport" content="width=device-width" /> ???<title>Index</title> ???<script src="~/Scripts/jquery-1.10.2.min.js"></script> ???@*<script src="~/Scripts/jquery.unobtrusive-ajax.min.js"></script>*@ ?????@*用了jquery.form.min.js可以不引用，即便引用了也没关系不影响，但是引用了的话需要注意的是会发生两次提交，在提交前执行return false即可，*@ ???<script src="~/Scripts/jquery.form.min.js"></script></head><body> ???<div> ???????<h3>mvc异步上传文件</h3> ???????@using (Ajax.BeginForm("UpFileload", "AjaxFileUpload", new AjaxOptions ???????{ ???????????Confirm = "确认上传吗？", ???????????HttpMethod = "post", ???????????OnSuccess = "func", ???????}, new { enctype = "multipart/form-data", id = "fileForm" })) ???????{ ???????????<input type="file" name="file" value="" /> ???????????@*<button type="submit">异步上传</button>*@ ???????????<button type="button">异步上传</button> ???????} ???</div></body></html><script> ???//当按钮被点击时执行异步提交 ???$("button[type=button]").click(() => { ???????//异步提交 ???????$("#fileForm").ajaxSubmit({ ????????????????url: "@Url.Action("UpFileload", "AjaxFileUpload")", ???????????type: "post", ???????????success: data => { ???????????????alert(data); ???????????}, ???????????error: () => { ???????????????alert("出错了"); ???????????} ???????}); ???});</script>后端action代码：
??/// <summary> ???????/// 异步文件上传 ???????/// </summary> ???????/// <param name="file">前端上传的文件</param> ???????/// <returns>文件路径</returns> ???????public ActionResult UpFileload(HttpPostedFileBase file) ???????{ ???????????//var myfile = Request.Files["file"]; //也可以拿到 ???????????var path = $"/UploadFile/{Guid.NewGuid() + file.FileName}"; ???????????file.SaveAs(Server.MapPath(path)); ?????//保存文件 ???????????return Content(path); ???????}jQuery的ajaxSubmit方法和ajax用法都差不多
第二种方式： $.ajaxFileUpload（{}） --->（先引入jQuery脚本）需要引入ajaxfileupload.js脚本 （这个方法是之前在项目过中用过的，不过当时我记得从网上下载下来的ajaxfileupload脚本会提示出错，好像是因为脚本里缺少什么函数来着，忘记了，然后我按照搜索到的解决方法修改了脚本）
因为是之前写的项目不是demo，代码量有点多就不一一贴上代码了，其实用法和第一种差不多，
$.ajaxFileUpload({ ???????????url: ‘@Url.Action("FileUpload", "Profile")‘, ???????????secureuri: false, ???????????fileElementId: ‘btn_file‘, ???//文件input标签id ???????????data: null, ???????????success: function (data, status) { ???????????????$.post("@Url.Action("MyData", "Profile")", null, ???????????????????html => { ???????????????????????$("#mybody").children().remove(); ???????????????????????$(html).appendTo("#mybody"); ???????????????????}); ???????????}, ???????????error: function (data, status, e) { ???????????????console.log(‘Error‘) ??????????????} ???????});最后贴上修改后的ajaxfileupload.js脚本的源码：
jQuery.extend({ ???handleError: function (s, xhr, status, e) { ???????// If a local callback was specified, fire it ???????if (s.error) { ???????????s.error.call(s.context || s, xhr, status, e); ???????} ???????// Fire the global callback ???????if (s.global) { ???????????(s.context ? jQuery(s.context) : jQuery.event).trigger( ???????????????"ajaxError", [xhr, s, e]); ???????} ???}, ???createUploadIframe: function(id, uri) ???{ ???????//create frame ???????var frameId = ‘jUploadFrame‘ + id; ???????if(window.ActiveXObject) { ???????????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; ???}, ???addOtherRequestsToForm: function(form,data) ???{ ???????// add extra parameter ???????var originalElement = $(‘<input type="hidden" name="" value="">‘); ???????for (var key in data) { ???????????name = key; ???????????value = data[key]; ???????????var cloneElement = originalElement.clone(); ???????????cloneElement.attr({‘name‘:name,‘value‘:value}); ???????????$(cloneElement).appendTo(form); ???????} ???????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 = new Date().getTime() ???????var form = jQuery.createUploadForm(id, s.fileElementId); ???????if ( s.data ) form = jQuery.addOtherRequestsToForm(form,s.data); ???????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 ???????????????????{ ???????????????????????$(io).remove(); ???????????????????????$(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‘; ???????????} ???????????$(form).submit(); ???????} catch(e) ???????{ ???????????jQuery.handleError(s, xml, null, e); ???????} ???????if(window.attachEvent){ ???????????document.getElementById(frameId).attachEvent(‘onload‘, uploadCallback); ???????} ???????else{ ???????????document.getElementById(frameId).addEventListener(‘load‘, uploadCallback, false); ???????} ???????return {abort: function () {}}; ???}, ???uploadHttpData: function( r, type ) { ???????var data = !type; ???????data = type == "xml" || data ? r.responseXML : r.responseText; ???????// If the type is "script", eval it in global context ???????if ( type == "script" ) ???????????jQuery.globalEval( data ); ???????// Get the JavaScript object, if JSON is used. ???????if ( type == "json" ) ???????{ ???????????// If you add mimetype in your response, ???????????// you have to delete the ‘<pre></pre>‘ tag. ???????????// The pre tag in Chrome has attribute, so have to use regex to remove ???????????var data = r.responseText; ???????????var rx = new RegExp("<pre.*?>(.*?)</pre>","i"); ???????????var am = rx.exec(data); ???????????//this is the desired data extracted ???????????var data = (am) ? am[1] : ""; ???//the only submatch or empty ???????????eval( "data = " + data ); ???????} ???????// evaluate scripts within html ???????if ( type == "html" ) ???????????jQuery("<div>").html(data).evalScripts(); ???????//alert($(‘param‘, data).each(function(){alert($(this).attr(‘value‘));})); ???????return data; ???}})感觉还是第一种比较舒服~~~不知道还有没有更简单好用的方式
Asp.Net Mvc异步上传文件的方式
原文地址：https://www.cnblogs.com/heheblog/p/net_study_20180805.html