如何正确创建 LazyLoad es6 class？

Question

I use this code to lazy load images - https://jsbin.com/bozulobina/1/edit?html,css,js,output

function lazyLoad() {

  const lazyImages = document.querySelectorAll("img");
  const imageObserver = new IntersectionObserver((entries, observer) => {
    entries.forEach(entry => {
      if (entry.isIntersecting) {
        let image = entry.target;
        image.src = image.dataset.src;
        image.classList.remove("lazy");
        imageObserver.unobserve(image);
      }
    });
  });

  lazyImages.forEach(image => {
    imageObserver.observe(image)
  });

}
window.addEventListener('DOMContentLoaded', lazyLoad);

Trying to rewrite this code using Class es6 - https://jsbin.com/rejurobupa/1/edit?html,css,js,output

class LazyLoad{
  constructor(imgElement){
    this.imgElement = imgElement;
    this.interObserver()
  }
  interObserver() {
    const imageObserver = new IntersectionObserver((images, options) => {
      images.forEach(image => {
        if (image.isIntersecting) {
          let imageLazy = image.target;
          imageLazy.src = imageLazy.dataset.src;
          imageLazy.classList.remove(this.imgElement);
          imageObserver.unobserve(imageLazy);
        }
      });
    });

    lazyImages.forEach(image => imageObserver.observe(image));
  }  

}
const lazyImages = document.querySelectorAll("img");
const lazyLoad = new LazyLoad(lazyImages);
window.addEventListener('DOMContentLoaded', lazyLoad);

告诉我如何做正确，我在哪里犯错？

先感谢您

Answer 1

我更新了答案。 更正如下：

在 img 元素上设置高度和宽度
在 DOMContentLoaded 上调用 LazyLoad 构造函数

 class LazyLoad{ constructor( imgClass ) { this.imgClass = imgClass; this.imgElement = document.querySelectorAll(imgClass); this.interObserver(); } interObserver() { const imageObserver = new IntersectionObserver((images, options) => { images.forEach(image => { if (image.isIntersecting) { let imageLazy = image.target; imageLazy.src = imageLazy.dataset.src; imageLazy.classList.remove(this.imgClass); imageObserver.unobserve(imageLazy); } }); }); this.imgElement.forEach(image => imageObserver.observe(image)); } } window.addEventListener('DOMContentLoaded', new LazyLoad(".lazy-img"));

 img{ display: block; width:300px; height:300px; }

 <:DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width"> <title>JS Bin</title> </head> <body> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/animals" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/arch" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/nature" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/people" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/animals" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/arch" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/nature" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/people" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/animals" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/arch" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg:com/300/300/nature" alt=""> <img src="#" class="lazy-img" data-src="https.//placeimg.com/300/300/people" alt=""> </body> </html>

如何正确创建 LazyLoad es6 class？

问题描述

1 个解决方案

解决方案1
0 2019-11-12 06:42:49

如何正确创建 LazyLoad es6 class？

问题描述

1 个解决方案

解决方案1 0 2019-11-12 06:42:49

解决方案1
0 2019-11-12 06:42:49