最近项目要js实现将数据导出excel文件，网上很多插件实现~~那个开心呀，谁知道后面数据量达到上万条时出问题：浏览器不仅卡死，导出的excel文件一直提示网络失败。。。。
debug调试发现var excel拼接的table字符串，超出了var的长度限制；幸好网上有前辈的解决方案~~~膜拜ing
参考网址：https://blog.csdn.net/b7410852963/article/details/51197552
需要自己去理解下 JavaScript Blob对象
/***导出excel文件 //例子: var data = [{ userName: 'lily', age: 28, job: "teacher", city: "广州" },{ userName: 'lucy', age: 19, job: "doctor", city: "深圳" }]; if (data == '')return; var title = [{ userName: '姓名' }, { job: '工作' }, { age: '年龄' }, { city: '城市' }]; toExcel("dataExport", data, title); ***/ /***toExcel: * FileName文件名 * JSONData导出的数据 * ShowLabel表头 */ var DownloadEvt = null; function toExcel(FileName, JSONData, ShowLabel) { var arrData = typeof JSONData != 'object' ? JSON.parse(JSONData) : JSONData; var docData = new StringBuffer(); // Header var innerHTML = new StringBuffer(); docData.append('<table><thead>'); for (var i = 0; i < ShowLabel.length; i++) { for (var key in ShowLabel[i]) { innerHTML.append('<td>' + ShowLabel[i][key] + '</td> '); } } docData.append('<tr> ' + innerHTML.toString() + '</tr>'); docData.append('</thead><tbody>'); // Row Vs Column for (var i = 0; i < arrData.length; i++) { var tdRow = new StringBuffer(); for (var y = 0; y < ShowLabel.length; y++) { for (var k in ShowLabel[y]) { if (ShowLabel[y].hasOwnProperty(k)) { tdRow.append('<td style="vnd.ms-excel.numberformat:@">' + (arrData[i][k] === null ? '' : arrData[i][k]) + '</td> '); } } } docData.append('<tr> ' + tdRow.toString() + '</tr>'); } docData.append('</tbody></table>'); console.log("docData:",docData); var docFile = new StringBuffer(); docFile.append('<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns="http://www.w3.org/TR/REC-html40">'); docFile.append('<meta http-equiv="content-type" content="application/vnd.ms-excel; charset=UTF-8">'); docFile.append("<head>"); docFile.append("<!--[if gte mso 9]>"); docFile.append("<xml>"); docFile.append("<x:ExcelWorkbook>"); docFile.append("<x:ExcelWorksheets>"); docFile.append("<x:ExcelWorksheet>"); docFile.append("<x:Name>"); docFile.append("{worksheet}"); docFile.append("</x:Name>"); docFile.append("<x:WorksheetOptions>"); docFile.append("<x:DisplayGridlines/>"); docFile.append("</x:WorksheetOptions>"); docFile.append("</x:ExcelWorksheet>"); docFile.append("</x:ExcelWorksheets>"); docFile.append("</x:ExcelWorkbook>"); docFile.append("</xml>"); docFile.append("<![endif]-->"); docFile.append("</head>"); docFile.append("<body>"); for (var i = 0; i < docData.content.length; i++) { docFile.append(docData.content[i].toString()); } // docFile.append( docData.toString()); docFile.append("</body>"); docFile.append("</html>"); console.log('docFile:',docFile); try { console.log('111111111') var blob = new Blob(docFile.content, { type: 'application/vnd.ms-excel;charset=UTF-8;' }); console.log("blob.size===" + blob.size); saveAs(blob, FileName + '.xlsx'); } catch (e) { console.log('22222222222') downloadFile(FileName + '.xlsx', 'data:application/vnd.ms-excel;base64,', docFile.toString()); } } function StringBuffer() { this.content = new Array; } StringBuffer.prototype.append = function(str) { this.content.push(str); } StringBuffer.prototype.prepend = function(str) { this.content.unshift(str); } StringBuffer.prototype.toString = function() { return this.content.join(""); } function saveAs(blob, filename) { var type = blob.type; var force_saveable_type = 'application/octet-stream'; if (type && type != force_saveable_type) { // 强制下载，而非在浏览器中打开 var slice = blob.slice || blob.webkitSlice || blob.mozSlice; blob = slice.call(blob, 0, blob.size, force_saveable_type); } var url = URL.createObjectURL(blob); var save_link = document.createElementNS('http://www.w3.org/1999/xhtml', 'a'); save_link.href = url; save_link.download = filename; console.log('save_link:',save_link); var event = document.createEvent('MouseEvents'); event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null); save_link.dispatchEvent(event); URL.revokeObjectURL(url); } function downloadFile(filename, header, data) { var ua = window.navigator.userAgent; if (ua.indexOf("MSIE ") > 0 || !!ua.match(/Trident.*rv:11./)) { // Internet Explorer (<= 9) workaround by Darryl (https://github.com/dawiong/tableExport.jquery.plugin) // based on sampopes answer on http://stackoverflow.com/questions/22317951 // ! Not working for json and pdf format ! var frame = document.createElement("iframe"); if (frame) { document.body.appendChild(frame); frame.setAttribute("style", "display:none"); frame.contentDocument.open("txt/html", "replace"); frame.contentDocument.write(data); frame.contentDocument.close(); frame.focus(); frame.contentDocument.execCommand("SaveAs", true, filename); document.body.removeChild(frame); } } else { var DownloadLink = document.createElement('a'); if (DownloadLink) { DownloadLink.style.display = 'none'; DownloadLink.download = filename; console.log((header + base64encode(data)).length); if (header.toLowerCase().indexOf("base64,") >= 0) DownloadLink.href = header + base64encode(data); else DownloadLink.href = encodeURIComponent(header + data); document.body.appendChild(DownloadLink); if (document.createEvent) { if (DownloadEvt == null) DownloadEvt = document.createEvent('MouseEvents'); DownloadEvt.initEvent('click', true, false); DownloadLink.dispatchEvent(DownloadEvt); } else if (document.createEventObject) DownloadLink.fireEvent('onclick'); else if (typeof DownloadLink.onclick == 'function') DownloadLink.onclick(); /*document.body.removeChild(DownloadLink);*/ } } } function base64encode(input) { var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; var output = ""; var chr1, chr2, chr3, enc1, enc2, enc3, enc4; var i = 0; input = utf8Encode(input); while (i < input.length) { chr1 = input.charCodeAt(i++); chr2 = input.charCodeAt(i++); chr3 = input.charCodeAt(i++); enc1 = chr1 >> 2; enc2 = ((chr1 & 3) << 4) | (chr2 >> 4); enc3 = ((chr2 & 15) << 2) | (chr3 >> 6); enc4 = chr3 & 63; if (isNaN(chr2)) { enc3 = enc4 = 64; } else if (isNaN(chr3)) { enc4 = 64; } output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4); } return output; } function utf8Encode(string) { string = string.replace(/x0dx0a/g, "x0a"); var utftext = ""; for (var n = 0; n < string.length; n++) { var c = string.charCodeAt(n); if (c < 128) { utftext += String.fromCharCode(c); } else if ((c > 127) && (c < 2048)) { utftext += String.fromCharCode((c >> 6) | 192); utftext += String.fromCharCode((c & 63) | 128); } else { utftext += String.fromCharCode((c >> 12) | 224); utftext += String.fromCharCode(((c >> 6) & 63) | 128); utftext += String.fromCharCode((c & 63) | 128); } } return utftext; }