关于计算首屏时间
利用performance.timing提供的数据:

通过DOMContentLoad或者performance来计算出首屏时间
// 方案一: document.addEventListener('DOMContentLoaded', (event) => { console.log('first contentful painting'); }); // 方案二: performance.getEntriesByName("first-contentful-paint")[0].startTime // performance.getEntriesByName("first-contentful-paint")[0] // 会返回一个 PerformancePaintTiming的实例,结构如下: { name: "first-contentful-paint", entryType: "paint", startTime: 507.80000002123415, duration: 0, };
