合肥師范學(xué)院

!img.classList.contains('no-lazy')); // 篩選掉包含.no-lazy的img元素 for (let i = 0; i < lazyImages.length; i++) { let url = lazyImages[i].getAttribute('src'); lazyImages[i].setAttribute('data-src', url); lazyImages[i].setAttribute('src', 'https://cdn.yun.sooce.cn/5/1598/png/1744965350314c4ca4238a0b923820dcc509a6f75849b.png'); lazyImages[i].classList.add('lazy-loading'); } lazyImages = document.querySelectorAll("img.lazy-loading"); let lazyImagesLength = lazyImages.length; let lazyLoad = function(image) { if (image.getBoundingClientRect().top < window.innerHeight && image.classList.contains('lazy-loading')) { image.src = image.dataset.src; image.classList.remove('lazy-loading'); lazyImagesLength--; } }; let lazyLoader = function() { if (lazyImagesLength > 0) { lazyImages.forEach(function(image) { lazyLoad(image); }); } }; window.addEventListener("scroll", lazyLoader); window.addEventListener("resize", lazyLoader); window.addEventListener("load", lazyLoader); lazyLoader();