js下载文件到本地各种方法总结

form.attr(\"style\ form.attr(\"target\

form.attr(\"method\ form.attr(\"action\ $(\"body\").append(form); form.submit();//表单提交}}

五、a标签的⽅式

function(url,name){

var a = document.createElement(\"a\"); a.download = name + \".xls\"; a.href = url;

$(\"body\").append(a); // 修复firefox中⽆法触发click a.click();

$(a).remove();}

六、假如后台给的⽂件流

function (formData, url, name) {

return new Promise((resolve, reject) => { var xhr = new XMLHttpRequest();

xhr.open(\"POST\也可以使⽤POST⽅式，根据接⼝ xhr.responseType = \"blob\"; // 返回类型blob

// 定义请求完成的处理函数，请求前也可以增加加载框/禁⽤下载按钮逻辑 xhr.onload = function () { // 请求完成

if (this.status === 200) { // 返回200

var blob = this.response;

var reader = new FileReader();

reader.readAsDataURL(blob); // 转换为base64，可以直接放⼊a表情href reader.onload = function (e) {

// 转换完成，创建⼀个a标签⽤于下载 var a = document.createElement(\"a\"); a.download = name + \".xls\"; a.href = e.target.result;

$(\"body\").append(a); // 修复firefox中⽆法触发click a.click(); resolve(200) $(a).remove(); }; } };

// 发送ajax请求

xhr.send(formData); })};

七、download.js（下⾯是download.js源码七、download.js（下⾯是download.js源码））

//download.js v4.2, by dandavis; 2008-2016. [CCBY2] see http://danml.com/download.html for tests/usage

// v1 landed a FF+Chrome compat way of downloading strings to local un-named files, upgraded to use a hidden frame and optional mime// v2 added named files via a[download], msSaveBlob, IE (10+) support, and window.URL support for larger+faster saves than dataURLs

// v3 added dataURL and Blob Input, bind-toggle arity, and legacy dataURL fallback was improved with force-download mime and base64 support. 3.1 improved safari handling.// v4 adds AMD/UMD, commonJS, and plain browser support

// v4.1 adds url download capability via solo URL argument (same domain/CORS only)

// v4.2 adds semantic variable names, long (over 2MB) dataURL support, and hidden by default temp anchors// https://github.com/rndme/download

(function (root, factory) {

if (typeof define === 'function' && define.amd) { // AMD. Register as an anonymous module. define([], factory);

} else if (typeof exports === 'object') {

// Node. Does not work with strict CommonJS, but

// only CommonJS-like environments that support module.exports, // like Node.

module.exports = factory(); } else {

// Browser globals (root is window) root.download = factory(); }

}(this, function () {

return function download(data, strFileName, strMimeType) {

var self = window, // this script is only for browsers anyway...

defaultMime = \"application/octet-stream\ mimeType = strMimeType || defaultMime, payload = data,

url = !strFileName && !strMimeType && payload, anchor = document.createElement(\"a\"), toString = function(a){return String(a);},

myBlob = (self.Blob || self.MozBlob || self.WebKitBlob || toString), fileName = strFileName || \"download\ blob, reader;

myBlob= myBlob.call ? myBlob.bind(self) : Blob ;

if(String(this)===\"true\"){ //reverse arguments, allowing download.bind(true, \"text/xml\ payload=[payload, mimeType]; mimeType=payload[0]; payload=payload[1]; }

if(url && url.length< 2048){ // if no filename and no mime, assume a url was passed as the only argument fileName = url.split(\"/\").pop().split(\"?\")[0];

anchor.href = url; // assign href prop to temp anchor

if(anchor.href.indexOf(url) !== -1){ // if the browser determines that it's a potentially valid url path: var ajax=new XMLHttpRequest(); ajax.open( \"GET\ ajax.responseType = 'blob'; ajax.onload= function(e){

download(e.target.response, fileName, defaultMime); };

setTimeout(function(){ ajax.send();}, 0); // allows setting custom ajax headers using the return: return ajax;

} // end if valid url? } // end if url?

//go ahead and download dataURLs right away if(/^data\\:[\\w+\\-]+\\/[\\w+\\-]+[,;]/.test(payload)){

if(payload.length > (1024*1024*1.999) && myBlob !== toString ){ payload=dataUrlToBlob(payload);

mimeType=payload.type || defaultMime; }else{

return navigator.msSaveBlob ? // IE10 can't do a[download], only Blobs: navigator.msSaveBlob(dataUrlToBlob(payload), fileName) :

saver(payload) ; // everyone else can save dataURLs un-processed }

}//end if dataURL passed?

blob = payload instanceof myBlob ? payload :

new myBlob([payload], {type: mimeType}) ;

function dataUrlToBlob(strUrl) { var parts= strUrl.split(/[:;,]/), type= parts[1],

decoder= parts[2] == \"base64\" ? atob : decodeURIComponent, binData= decoder( parts.pop() ), mx= binData.length, i= 0,

uiArr= new Uint8Array(mx);

for(i;ireturn new myBlob([uiArr], {type: type}); }

function saver(url, winMode){

if ('download' in anchor) { //html5 A[download] anchor.href = url;

anchor.setAttribute(\"download\ anchor.className = \"download-js-link\"; anchor.innerHTML = \"downloading...\"; anchor.style.display = \"none\";

document.body.appendChild(anchor); setTimeout(function() { anchor.click();

document.body.removeChild(anchor);

if(winMode===true){setTimeout(function(){ self.URL.revokeObjectURL(anchor.href);}, 250 );} }, 66);

return true; }

// handle non-a[download] safari as best we can:

if(/(Version)\\/(\\d+)\\.(\\d+)(?:\\.(\\d+))?.*Safari\\//.test(navigator.userAgent)) { url=url.replace(/^data:([\\w\\/\\-\\+]+)/, defaultMime);

if(!window.open(url)){ // popup blocked, offer direct download:

if(confirm(\"Displaying New Document\\n\\nUse Save As... to download, then click back to return to this page.\")){ location.href=url; } }

return true; }

//do iframe dataURL download (old ch+FF): var f = document.createElement(\"iframe\"); document.body.appendChild(f);

if(!winMode){ // force a mime that will download:

url=\"data:\"+url.replace(/^data:([\\w\\/\\-\\+]+)/, defaultMime); }

f.src=url;

setTimeout(function(){ document.body.removeChild(f); }, 333);

}//end saver

if (navigator.msSaveBlob) { // IE10+ : (has Blob, but not a[download] or URL) return navigator.msSaveBlob(blob, fileName); }

if(self.URL){ // simple fast and modern way using Blob and URL: saver(self.URL.createObjectURL(blob), true); }else{

// handle non-Blob()+non-URL browsers:

if(typeof blob === \"string\" || blob.constructor===toString ){ try{

return saver( \"data:\" + mimeType + \";base64,\" + self.btoa(blob) ); }catch(y){

return saver( \"data:\" + mimeType + \ } }

// Blob but not URL support: reader=new FileReader(); reader.onload=function(e){ saver(this.result); };

reader.readAsDataURL(blob); }

return true;

}; /* end download() */}));

⽤法：

download(fileUrl,name,\"video/mp4\");具体更多的⽤法请参考官⽹，

注意 download.js第⼀个参数 是数据流，不是像oss那样的⽂件地址