js-magnifying glass effect_html/css_WEB-ITnose
JD or Taobao’s specific products have a magnifying glass effect. Although there are many similar plug-ins on the Internet, there are many inconveniences in applying them to projects. If you take some time to write a similar plug-in yourself and accumulate the code, why not do it!! let'go:
- I plan to encapsulate this special effect into a plug-in. First implement the most basic algorithm, and then encapsulate it step by step:
Final effect:
html code:
<div id="Magnifier"></div>
css code:
<style> * { margin: 0; padding: 0; } </style>
It seems there is nothing, let’s start with our powerful js journey:
javascript code:
function createElement(MagnifierId, sImg, bImg) { var Magnifier = $(MagnifierId); Magnifier.style.position = 'relative'; //小图div var smallDiv = $Create("div"); smallDiv.setAttribute("id", "small"); smallDiv.style.position = "absolute"; //遮罩层 var mask = $Create("div"); mask.setAttribute("id", "mask"); mask.style.position = "absolute"; //镜片 var mirror = $Create("div"); mirror.setAttribute("id", "mirror"); mirror.style.opacity = 0.3; mirror.style.position = "absolute"; mirror.style.display = "none"; //小图 var smallImg = $Create("img"); smallImg.setAttribute("src", sImg); smallImg.setAttribute("id", "smallImg"); smallImg.onload = function () { //如果没设置放大镜的height或者width 根据小图大小设置放大镜大小 if (!Magnifier.offsetHeight) { Magnifier.style.width = this.offsetWidth+"px"; Magnifier.style.height = this.offsetHeight + "px"; } //遮罩层大小和小图一样 mask.style.opacity = "0"; mask.style.width = this.width + 'px'; mask.style.height = this.height + "px"; mask.style.zIndex = 2; bigDiv.style.left = this.width + 5 + "px"; bigDiv.style.top = "-5px"; } smallDiv.appendChild(mask); smallDiv.appendChild(mirror); smallDiv.appendChild(smallImg); //视窗 var bigDiv = $Create("div"); bigDiv.setAttribute("id", "big"); bigDiv.style.position = "absolute"; bigDiv.style.overflow = "hidden"; bigDiv.style.display = "none"; var bigImg = $Create("img"); bigImg.setAttribute("src", bImg); bigImg.setAttribute("id", "bigImg"); bigImg.style.position = "absolute"; bigDiv.appendChild(bigImg); Magnifier.appendChild(smallDiv); Magnifier.appendChild(bigDiv); } function setMagnifierStyle(mirrorStyle,shichuangStyle) { //mirror for (var item in mirrorStyle) { mirror.style[item] = mirrorStyle[item]; } for (var item in shichuangStyle) { $("big").style[item] = shichuangStyle[item]; } } function registerEvent() { $("mask").onmouseover = function () { $("big").style.display = "block"; mirror.style.display = "block"; } $("mask").onmouseout = function () { $("big").style.display = "none"; mirror.style.display = "none"; } $("mask").onmousemove = function (evt) { var oEvent = evt || event; var disX = oEvent.offsetX; var disY = oEvent.offsetY; var mirrorLeft = disX - mirror.offsetWidth / 2; var mirrorTop = disY - mirror.offsetHeight / 2; if (mirrorLeft < 0) { mirrorLeft = 0; } else if (mirrorLeft > mask.offsetWidth - mirror.offsetWidth) { mirrorLeft = mask.offsetWidth - mirror.offsetWidth; } if (mirrorTop < 0) { mirrorTop = 0; } else if (mirrorTop > mask.offsetHeight - mirror.offsetHeight) { mirrorTop = mask.offsetHeight - mirror.offsetHeight; } mirror.style.top = mirrorTop + "px"; mirror.style.left = mirrorLeft + "px"; var paX = mirrorTop / (mask.offsetHeight - mirror.offsetHeight); var paY = mirrorLeft / (mask.offsetWidth - mirror.offsetWidth); $("bigImg").style.top = -paX * ($("bigImg").offsetHeight - $("big").offsetHeight) + "px"; $("bigImg").style.left = -paY * ($("bigImg").offsetWidth - $("big").offsetWidth) + "px"; } } function $(id) { return document.getElementById(id); } function $Create(type) { return document.createElement(type); }
Finally, make a small onload call:
window.onload = function () { createElement("Magnifier", "images/Magnifier/small.jpg", "images/Magnifier/big.jpg"); setMagnifierStyle({ "width": "30px", "height": "30px", "backgroundColor": "#fff" }, { "width": "250px", "height": "250px" }); registerEvent(); }
The effect is finally out,
2. Next let’s encapsulate:
Magnifer class code:
function Magnifier( MagnifierId, //放大镜容器ID sImg, //小图片src bImg, //大图片src mirrorStyle, //小图片里镜片样式,json格式数据 ViewStyle //预览视窗样式,json格式数据 ) { var _this = this; this.MagnifierContainer = null; //容器 this.smallDiv = null; //小图容器 this.mask = null; //小图遮罩层 this.mirror = null; //小图镜片 this.smallImg = null; //小图 this.bigDiv = null; //预览视图 this.bigImg = null; //大图 var init = function () { _this.MagnifierContainer = _this.$(MagnifierId); _this.createElement(sImg, bImg); _this.setMagnifierStyle(mirrorStyle, ViewStyle); _this.MainEvent(); } init(); } Magnifier.prototype.createElement = function (sImg, bImg) { var _this = this; var $Create = this.$Create; this.MagnifierContainer.style.position = 'relative'; //脱离文档流,视情况修改 this.smallDiv = $Create("div"); this.smallDiv.setAttribute("id", "small"); this.smallDiv.style.position = "absolute"; this.mask = $Create("div"); this.mask.setAttribute("id", "mask"); this.mask.style.position = "absolute"; this.mirror = $Create("div"); this.mirror.setAttribute("id", "mirror"); this.mirror.style.opacity = 0.3; this.mirror.style.position = "absolute"; this.mirror.style.display = "none"; this.smallImg = $Create("img"); this.smallImg.setAttribute("src", sImg); this.smallImg.setAttribute("id", "smallImg"); this.smallImg.onload = function () { //如果没设置放大镜的height或者width 根据小图大小设置放大镜大小 if (!_this.MagnifierContainer.offsetHeight) { _this.MagnifierContainer.style.width = this.offsetWidth + "px"; _this.MagnifierContainer.style.height = this.offsetHeight + "px"; } //遮罩层大小和小图一样 _this.mask.style.opacity = "0"; _this.mask.style.width = this.offsetWidth + 'px'; _this.mask.style.height = this.offsetHeight + "px"; _this.mask.style.zIndex = 2; _this.bigDiv.style.left = this.offsetWidth + 5 + "px"; _this.bigDiv.style.top = "-5px"; } this.smallDiv.appendChild(this.mask); this.smallDiv.appendChild(this.mirror); this.smallDiv.appendChild(this.smallImg); this.bigDiv = $Create("div"); this.bigDiv.setAttribute("id", "big"); this.bigDiv.style.position = "absolute"; this.bigDiv.style.overflow = "hidden"; this.bigDiv.style.display = "none"; this.bigImg = $Create("img"); this.bigImg.setAttribute("src", bImg); this.bigImg.setAttribute("id", "bigImg"); this.bigImg.style.position = "absolute"; this.bigDiv.appendChild(this.bigImg); this.MagnifierContainer.appendChild(this.smallDiv); this.MagnifierContainer.appendChild(this.bigDiv); } Magnifier.prototype.setMagnifierStyle = function (mirrorStyle, ViewStyle) { for (var item in mirrorStyle) { this.mirror.style[item] = mirrorStyle[item]; } delete item; for (var item in ViewStyle) { this.bigDiv.style[item] = ViewStyle[item]; } } Magnifier.prototype.MainEvent = function () { var _this = this; this.mask.onmouseover = function () { _this.bigDiv.style.display = "block"; _this.mirror.style.display = "block"; } this.mask.onmouseout = function () { _this.bigDiv.style.display = "none"; _this.mirror.style.display = "none"; } this.mask.onmousemove = function (evt) { var oEvent = evt || event; var disX = oEvent.offsetX || oEvent.layerX; //兼容ff var disY = oEvent.offsetY || oEvent.layerY; var mirrorLeft = disX - _this.mirror.offsetWidth / 2; var mirrorTop = disY - _this.mirror.offsetHeight / 2; if (mirrorLeft < 0) { mirrorLeft = 0; } else if (mirrorLeft > this.offsetWidth - _this.mirror.offsetWidth) { mirrorLeft = this.offsetWidth - mirror.offsetWidth; } if (mirrorTop < 0) { mirrorTop = 0; } else if (mirrorTop > this.offsetHeight - _this.mirror.offsetHeight) { mirrorTop = this.offsetHeight - _this.mirror.offsetHeight; } _this.mirror.style.top = mirrorTop + "px"; _this.mirror.style.left = mirrorLeft + "px"; var paX = mirrorTop / (this.offsetHeight - _this.mirror.offsetHeight); var paY = mirrorLeft / (this.offsetWidth - _this.mirror.offsetWidth); _this.bigImg.style.top = -paX * (_this.bigImg.offsetHeight - _this.bigDiv.offsetHeight) + "px"; _this.bigImg.style.left = -paY * (_this.bigImg.offsetWidth - _this.bigDiv.offsetWidth) + "px"; } } Magnifier.prototype.$ = function (id) { return document.getElementById(id); } Magnifier.prototype.$Create = function (type) { return document.createElement(type); }
Finally under the onload call:
window.onload = function () { new Magnifier( "Magnifier", "images/Magnifier/small.jpg", "images/Magnifier/big.jpg", { "width": "30px", "height": "30px", "backgroundColor": "#fff" }, { "width": "250px", "height": "250px" } ); }

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

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

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



The article discusses the HTML <progress> element, its purpose, styling, and differences from the <meter> element. The main focus is on using <progress> for task completion and <meter> for stati

HTML is suitable for beginners because it is simple and easy to learn and can quickly see results. 1) The learning curve of HTML is smooth and easy to get started. 2) Just master the basic tags to start creating web pages. 3) High flexibility and can be used in combination with CSS and JavaScript. 4) Rich learning resources and modern tools support the learning process.

The article discusses the HTML <datalist> element, which enhances forms by providing autocomplete suggestions, improving user experience and reducing errors.Character count: 159

The article discusses the viewport meta tag, essential for responsive web design on mobile devices. It explains how proper use ensures optimal content scaling and user interaction, while misuse can lead to design and accessibility issues.

The article discusses the <iframe> tag's purpose in embedding external content into webpages, its common uses, security risks, and alternatives like object tags and APIs.

HTML defines the web structure, CSS is responsible for style and layout, and JavaScript gives dynamic interaction. The three perform their duties in web development and jointly build a colorful website.

The article discusses the HTML <meter> element, used for displaying scalar or fractional values within a range, and its common applications in web development. It differentiates <meter> from <progress> and ex

WebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.
