Home Web Front-end HTML Tutorial Lazy loading problem of images

Lazy loading problem of images

Jun 26, 2017 pm 03:18 PM
load picture question

When we browse large shopping websites such as Taobao and JD.com, many pictures often appear, and the pictures cost us a lot of traffic.

How do we solve this problem when writing web pages? At this time, we need to use the problem of lazy loading of our images, which not only solves the traffic problem, but also improves performance and so on.

Let’s take a look at the problem with lazy loading of images.

<span style="font-size: 18px"><!DOCTYPE html></span><br><span style="font-size: 18px"><html lang="en"></span><br><span style="font-size: 18px"><head></span><br><span style="font-size: 18px">    <meta charset="UTF-8"></span><br><span style="font-size: 18px">    <title>Title</title></span><br><span style="font-size: 18px">    <style></span><br><span style="font-size: 18px">        *{</span><br><span style="font-size: 18px">            margin: 0;</span><br><span style="font-size: 18px">            padding: 0;</span><br><span style="font-size: 18px">            list-style-type: none;</span><br><span style="font-size: 18px">        }</span><br><span style="font-size: 18px">        html,body{</span><br><span style="font-size: 18px">            width: 100%;</span><br><span style="font-size: 18px">            height: 100%;</span><br><span style="font-size: 18px">        }</span><br><span style="font-size: 18px">        #div div{</span><br><span style="font-size: 18px">            width: 400px;</span><br><span style="font-size: 18px">            height: 500px;</span><br><span style="font-size: 18px">            /*border:1px solid #000;*/</span><br><span style="font-size: 18px">            display: inline-block;</span><br><span style="font-size: 18px">            margin:10px;</span><br><span style="font-size: 18px">        }</span><br><span style="font-size: 18px">        img{</span><br><span style="font-size: 18px">            width: 100%;</span><br><span style="font-size: 18px">            height: 100%;</span><br><span style="font-size: 18px">        }</span><br><span style="font-size: 18px">    </style></span><br><span style="font-size: 18px">    <script></span><br><span style="font-size: 18px">        // 获取距离父级距离</span><br><span style="font-size: 18px">        function getPos(obj) {</span><br><span style="font-size: 18px">            var t=0;//先声明两个变量  用来存储距离上面的高度  距离左边的高度</span><br><span style="font-size: 18px">            var l=0;</span><br><span style="font-size: 18px">            while (obj){//循环判断这个元素是否存在,存在才执行这个方法</span><br><span style="font-size: 18px">                t+=obj.offsetTop; // 加上距离父级的距离</span><br><span style="font-size: 18px">                l+=obj.offsetLeft;</span><br><span style="font-size: 18px">                obj=obj.offsetParent;// 有父级让他变成他的父级</span><br><span style="font-size: 18px">            }</span><br><span style="font-size: 18px">            return {left:l,top:t}; //把值传出去</span><br><span style="font-size: 18px">        }</span><br><br><span style="font-size: 18px">        window.onload=window.onscroll=function () {//滚动的时候和页面加载时执行的一样</span><br><span style="font-size: 18px">            var aImg=document.getElementsByTagName('img');//获取所有的元素img元素</span><br><span style="font-size: 18px">            var oSCrollT=document.body.scrollTop || document.documentElement.scrollTop;// 滚动条滚动高度</span><br><span style="font-size: 18px">            var oClh=document.documentElement.clientHeight;//可视区的高度</span><br><span style="font-size: 18px">            var oScr=oSCrollT + oClh; // 滚动条高度 + 可视区的高度</span><br><span style="font-size: 18px">            for(var i=0;i<aImg.length;i++){ //循环所有的img,把它距离页面顶部的距离 和  滚动高度+可视区的高度进行比较</span><br/><span style="font-size: 18px">                if(oScr > getPos(aImg[i]).top){</span><br><span style="font-size: 18px">                    aImg[i].src=aImg[i].getAttribute('_src');  //给src属性赋值</span><br><span style="font-size: 18px">                }</span><br><span style="font-size: 18px">            }</span><br><span style="font-size: 18px">        }</span><br><span style="font-size: 18px">    </script></span><br><span style="font-size: 18px"></head></span><br><span style="font-size: 18px"><body></span><br><span style="font-size: 18px">    <div id="div"></span><br><span style="font-size: 18px">        <div><img _src="img/1.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/2.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/3.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/4.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/5.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/6.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/7.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/8.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/9.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/10.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/11.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/12.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/13.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/14.jpg"></div></span><br><span style="font-size: 18px">        <div><img _src="img/15.jpg"></div></span><br><span style="font-size: 18px">    </div></span><br><span style="font-size: 18px"></body></span><br><span style="font-size: 18px"></html><br>今天的内容就到这里,你学会了吗?</span>
Copy after login

The above is the detailed content of Lazy loading problem of images. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to solve the problem of automatically saving pictures when publishing on Xiaohongshu? Where is the automatically saved image when posting? How to solve the problem of automatically saving pictures when publishing on Xiaohongshu? Where is the automatically saved image when posting? Mar 22, 2024 am 08:06 AM

With the continuous development of social media, Xiaohongshu has become a platform for more and more young people to share their lives and discover beautiful things. Many users are troubled by auto-save issues when posting images. So, how to solve this problem? 1. How to solve the problem of automatically saving pictures when publishing on Xiaohongshu? 1. Clear the cache First, we can try to clear the cache data of Xiaohongshu. The steps are as follows: (1) Open Xiaohongshu and click the &quot;My&quot; button in the lower right corner; (2) On the personal center page, find &quot;Settings&quot; and click it; (3) Scroll down and find the &quot;Clear Cache&quot; option. Click OK. After clearing the cache, re-enter Xiaohongshu and try to post pictures to see if the automatic saving problem is solved. 2. Update the Xiaohongshu version to ensure that your Xiaohongshu

How to post pictures in TikTok comments? Where is the entrance to the pictures in the comment area? How to post pictures in TikTok comments? Where is the entrance to the pictures in the comment area? Mar 21, 2024 pm 09:12 PM

With the popularity of Douyin short videos, user interactions in the comment area have become more colorful. Some users wish to share images in comments to better express their opinions or emotions. So, how to post pictures in TikTok comments? This article will answer this question in detail and provide you with some related tips and precautions. 1. How to post pictures in Douyin comments? 1. Open Douyin: First, you need to open Douyin APP and log in to your account. 2. Find the comment area: When browsing or posting a short video, find the place where you want to comment and click the &quot;Comment&quot; button. 3. Enter your comment content: Enter your comment content in the comment area. 4. Choose to send a picture: In the interface for entering comment content, you will see a &quot;picture&quot; button or a &quot;+&quot; button, click

6 Ways to Make Pictures Sharper on iPhone 6 Ways to Make Pictures Sharper on iPhone Mar 04, 2024 pm 06:25 PM

Apple's recent iPhones capture memories with crisp detail, saturation and brightness. But sometimes, you may encounter some issues that may cause the image to look less clear. While autofocus on iPhone cameras has come a long way, allowing you to take photos quickly, the camera can mistakenly focus on the wrong subject in certain situations, making the photo blurry in unwanted areas. If your photos on your iPhone look out of focus or lack sharpness overall, the following post should help you make them sharper. How to Make Pictures Clearer on iPhone [6 Methods] You can try using the native Photos app to clean up your photos. If you want more features and options

How to make ppt pictures appear one by one How to make ppt pictures appear one by one Mar 25, 2024 pm 04:00 PM

In PowerPoint, it is a common technique to display pictures one by one, which can be achieved by setting animation effects. This guide details the steps to implement this technique, including basic setup, image insertion, adding animation, and adjusting animation order and timing. Additionally, advanced settings and adjustments are provided, such as using triggers, adjusting animation speed and order, and previewing animation effects. By following these steps and tips, users can easily set up pictures to appear one after another in PowerPoint, thereby enhancing the visual impact of the presentation and grabbing the attention of the audience.

Error loading plugin in Illustrator [Fixed] Error loading plugin in Illustrator [Fixed] Feb 19, 2024 pm 12:00 PM

When launching Adobe Illustrator, does a message about an error loading the plug-in pop up? Some Illustrator users have encountered this error when opening the application. The message is followed by a list of problematic plugins. This error message indicates that there is a problem with the installed plug-in, but it may also be caused by other reasons such as a damaged Visual C++ DLL file or a damaged preference file. If you encounter this error, we will guide you in this article to fix the problem, so continue reading below. Error loading plug-in in Illustrator If you receive an "Error loading plug-in" error message when trying to launch Adobe Illustrator, you can use the following: As an administrator

What should I do if the images on the webpage cannot be loaded? 6 solutions What should I do if the images on the webpage cannot be loaded? 6 solutions Mar 15, 2024 am 10:30 AM

Some netizens found that when they opened the browser web page, the pictures on the web page could not be loaded for a long time. What happened? I checked that the network is normal, so where is the problem? The editor below will introduce to you six solutions to the problem that web page images cannot be loaded. Web page images cannot be loaded: 1. Internet speed problem The web page cannot display images. It may be because the computer's Internet speed is relatively slow and there are more softwares opened on the computer. And the images we access are relatively large, which may be due to loading timeout. As a result, the picture cannot be displayed. You can turn off the software that consumes more network speed. You can go to the task manager to check. 2. Too many visitors. If the webpage cannot display pictures, it may be because the webpages we visited were visited at the same time.

How to convert pdf documents into jpg images with Foxit PDF Reader - How to convert pdf documents into jpg images with Foxit PDF Reader How to convert pdf documents into jpg images with Foxit PDF Reader - How to convert pdf documents into jpg images with Foxit PDF Reader Mar 04, 2024 pm 05:49 PM

Are you also using Foxit PDF Reader software? So do you know how Foxit PDF Reader converts pdf documents into jpg images? The following article brings you how Foxit PDF Reader converts pdf documents into jpg images. For those who are interested in the method of converting jpg images, please come and take a look below. First start Foxit PDF Reader, then find "Features" on the top toolbar, and then select the "PDF to Others" function. Next, open a web page called "Foxit PDF Online Conversion". Click the "Login" button on the upper right side of the page to log in, and then turn on the "PDF to Image" function. Then click the upload button and add the pdf file you want to convert into an image. After adding it, click "Start Conversion"

How to arrange two pictures side by side in wps document How to arrange two pictures side by side in wps document Mar 20, 2024 pm 04:00 PM

When using WPS office software, we found that not only one form is used, tables and pictures can be added to the text, pictures can also be added to the table, etc. These are all used together to make the content of the entire document look richer. , if you need to insert two pictures into the document and they need to be arranged side by side. Our next course can solve this problem: how to place two pictures side by side in a wps document. 1. First, you need to open the WPS software and find the picture you want to adjust. Left-click the picture and a menu bar will pop up, select &quot;Page Layout&quot;. 2. Select &quot;Tight wrapping&quot; in text wrapping. 3. After all the pictures you need are confirmed to be set to &quot;Tight text wrapping&quot;, you can drag the pictures to the appropriate position and click on the first picture.

See all articles