记录几个常用的函数封装

class Utils { /** 日期格式化 * @param {string} formmat - 日期格式 * @param {date} timestamp - 要转换的时间 * @return {string} * */ static formmatData(formmat='Y-M-D h:m:s', timestamp = Date.now()){ let date = new Date(timestamp) let deteInfo = { Y: date.getFullYear(), M: date.getMonth()+1, D: date.getDate(), h: date.getHours(), m: date.getHours(), s: date.getSeconds() } let formatNumber = (n) => n > 10 ? n : '0' + n; let res = formmat .replace('Y', deteInfo.Y) .replace('M', formatNumber(deteInfo.M)) .replace('D', formatNumber(deteInfo.D)) .replace('h', formatNumber(deteInfo.h)) .replace('m', formatNumber(deteInfo.m)) .replace('s', formatNumber(deteInfo.s)) return res; } //性能分析 static xncs(){ setTimeout(()=>{ let t = performance.timing, m = performance.memory console.table({ 'DNS查询耗时': (t.domainLookupEnd - t.domainLookupStart).toFixed(0), 'TCP链接耗时': (t.connectEnd - t.connectStart).toFixed(0), 'request请求耗时': (t.responseEnd - t.responseStart).toFixed(0), '解析dom树耗时': (t.domComplete - t.domInteractive).toFixed(0), '白屏时间': (t.responseStart - t.navigationStart).toFixed(0), 'domready时间': (t.domContentLoadedEventEnd - t.navigationStart).toFixed(0), 'onload时间': (t.loadEventEnd - t.navigationStart).toFixed(0), 'js内存使用占比': m ? (m.usedJSHeapSize / m.totalJSHeapSize * 100).toFixed(2) + '%' : undefined }) }) } /** 防抖 * @param {function} func - 执行函数 * @param {number} wait - 等待时间 * @param {boolean} immediate - 是否立即执行 * @return {function} * */ static debounce(func, wait=300, immediate){ let timer, ctx; let later = (arg) => setTimeout(() => { func.apply(ctx, arg) timer = ctx = null }, wait); return function(...arg){ if(!timer){ timer = later(arg) ctx = this if(immediate){ func.apply(ctx,arg) } }else{ clearTimeout(timer) timer = later(arg) } } } /** 节流 * @param {function} func - 执行函数 * @param {number} delay - 延迟时间 * @return {function} * */ static throttle(func, delay){ let timer = null return function(...arg){ if(!timer){ timer = setTimeout(() => { func.apply(this, arg) timer = null }, delay) } } } /** * @param {string} filename - 下载时的文件名 * @param {string} data - base64字符串 */ static downloadFile(filename, data){ let downloadLink = document.createElement('a'); if ( downloadLink ){ document.body.appendChild(downloadLink); downloadLink.style = 'display: none'; downloadLink.download = filename; downloadLink.href = data; if ( document.createEvent ){ let 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); } } /** 判断是不是浏览器 * * */ static isPCBroswer() { let e = window.navigator.userAgent.toLowerCase() , t = "ipad" == e.match(/ipad/i) , i = "iphone" == e.match(/iphone/i) , r = "midp" == e.match(/midp/i) , n = "rv:1.2.3.4" == e.match(/rv:1.2.3.4/i) , a = "ucweb" == e.match(/ucweb/i) , o = "android" == e.match(/android/i) , s = "windows ce" == e.match(/windows ce/i) , l = "windows mobile" == e.match(/windows mobile/i); return !(t || i || r || n || a || o || s || l) } /** 识别浏览器以及平台 * */ static getPlatformInfo(){ //运行环境是浏览器 let inBrowser = typeof window !== 'undefined'; //运行环境是微信 let inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform; let weexPlatform = inWeex && WXEnvironment.platform.toLowerCase(); //浏览器 UA 判断 let UA = inBrowser && window.navigator.userAgent.toLowerCase(); if(UA){ let platforms = { IE: /msie|trident/.test(UA), IE9: UA.indexOf('msie 9.0') > 0, Edge: UA.indexOf('edge/') > 0, Android: UA.indexOf('android') > 0 || (weexPlatform === 'android'), IOS: /iphone|ipad|ipod|ios/.test(UA) || (weexPlatform === 'ios'), Chrome: /chrome\/\d+/.test(UA) && !(UA.indexOf('edge/') > 0), } for (const key in platforms) { if (platforms.hasOwnProperty(key)) { if(platforms[key]) return key } } } } }