Javascript:在没有Jquery或插件的情况下放大鼠标悬停

Javascript: Zoom in on mouseover WITHOUT Jquery or plugins

本文关键字:情况下 放大 鼠标 悬停 插件 Jquery Javascript      更新时间:2023-09-26

我已经到处找了好几个星期了,但我根本找不到什么东西来告诉我做错了什么,甚至找不到如何继续。目标是为具有小图像的产品创建一个类似于亚马逊鼠标悬停放大的功能。

我目前不知道如何继续,尽管我知道我需要两张图像——一张是"放大"大小,另一张则是"缩小"大小我没有使用Jquery-我不能根据雇主的要求将其或任何插件安装到网站上。我基本上是在要求更难的答案,我提前为此道歉。我必须从头开始做这件事警告:我是一名编程专业的学生。随你怎么想。

我有HTML和CSS脚本,因为我们这里实际上没有IDE,所以我在codecademy的项目部分做这件事,否则我必须完全现场编程。你可以在这里找到我的代码,但我也会在下面发布代码,因为该链接使用过程保存,所以它必然会有更改的代码。

注意:我最初有它,所以灰色的盒子在相对中心跟随我的鼠标。它在移动时闪烁,但它在工作。尽管目前决定不这样做,至少在我的工作电脑上是这样。我还没有在我的个人电脑上测试过。

编辑:代码在我的Surface Pro 3上运行,尽管它确实跟随鼠标离开了图像(这是暂时的,是我随机抓取的)。我不确定为什么代码在我的工作电脑上不起作用,尽管这很可能是因为它是Macintosh OSX版本10.6.8…

HTML代码:

<!DOCTYPE html>
<html>
<head>
    <link rel='stylesheet' href='style.css'/>
    <script src='script.js'></script>
</head>
<body>
<img id="imgZoom" onmousemove="zoomIn()" onmouseout="zoomOut()" src="http://ginger-mum.com/wp-content/uploads/2015/10/3633-1269758855-0da5042c33400a811a5d766be4579cb8.jpg">
<div id="overlay" onmousemove="zoomIn()"></div>
</body>
</html>

CSS代码:

#imgZoom {
    height: 300;
}
#overlay {
    visibility: hidden;
    position: absolute;
    left: 0px;
    top: 0px;
    width:20%;
    height:20%;
    padding: 25px;
    border: 5px solid gray;
    background-color: white;
    opacity:0.4;
    text-align:center;
    z-index: 1000;
}

Javascript代码:

function zoomIn()
{
    var element = document.getElementById("overlay");
    element.style.visibility = "visible";
    var x = event.clientX;     // Get the horizontal coordinate
    var y = event.clientY;     // Get the vertical coordinate
    element.style.top = y - 80;
    element.style.left = x - 80;
}
function zoomOut()
{
    var element = document.getElementById("overlay");
    element.style.visibility = "hidden";
}

您可以通过在鼠标上播放背景位置来完成,只需在DEMO 上移动鼠标上的背景位置

function zoomIn(event) {
  var element = document.getElementById("overlay");
  element.style.display = "inline-block";
  var img = document.getElementById("imgZoom");
  var posX = event.offsetX ? (event.offsetX) : event.pageX - img.offsetLeft;
  var posY = event.offsetY ? (event.offsetY) : event.pageY - img.offsetTop;
  element.style.backgroundPosition = (-posX * 4) + "px " + (-posY * 4) + "px";
}
function zoomOut() {
  var element = document.getElementById("overlay");
  element.style.display = "none";
}
#overlay {
  border: 1px solid black;
  width: 200px;
  height: 200px;
  display: inline-block;
  background-image: url('https://via.placeholder.com/400.png');
  background-repeat: no-repeat;
}
<img id="imgZoom" width="200px" height="200px" onmousemove="zoomIn(event)" onmouseout="zoomOut()" src="https://via.placeholder.com/200.png">
<div id="overlay" onmousemove="zoomIn(event)"></div>

这对我有用:(这里是一个JSFiddle)

#imgZoom {
    height: 300;
}
img#imgZoom:hover {
    position: relative;
    -webkit-transform: scale(1.5);
    -ms-transform: scale(1.5);
    -o-transform: scale(1.5);
    transform: scale(1.5);
    z-index: 1000;
}

你也可以添加这个来获得一个很酷的过渡效果:

* {
    -webkit-transition: all 0.5s ease-in-out;
    -moz-transition: all 0.5s ease-in-out;
    -ms-transition: all 0.5s ease-in-out;
    -o-transition: all 0.5s ease-in-out;
    transition: all 0.5s ease-in-out;
}

*此外,您不仅可以将相同的逻辑应用于图像,还可以将其应用于div。

function zoomIn(event) {
  var element = document.getElementById("overlay");
  element.style.display = "inline-block";
  var img = document.getElementById("imgZoom");
  var posX = event.offsetX ? (event.offsetX) : event.pageX - img.offsetLeft;
  var posY = event.offsetY ? (event.offsetY) : event.pageY - img.offsetTop;
  element.style.backgroundPosition = (-posX * 4) + "px " + (-posY * 4) + "px";
}
function zoomOut() {
  var element = document.getElementById("overlay");
  element.style.display = "none";
}
#overlay {
  border: 1px solid black;
  width: 100px;
  height: 100px;
  display: inline-block;
  background-image: url('http://ginger-mum.com/wp-content/uploads/2015/10/3633-1269758855-0da5042c33400a811a5d766be4579cb8.jpg');
  background-repeat: no-repeat;
}
<img id="imgZoom" width="200px" height="200px" onmousemove="zoomIn(event)" onmouseout="zoomOut()" src="http://ginger-mum.com/wp-content/uploads/2015/10/3633-1269758855-0da5042c33400a811a5d766be4579cb8.jpg">
<div id="overlay" onmousemove="zoomIn(event)"></div>

试试这个

window.addEventListener("load", imageZoom("my-image"));
function imageZoom(imgID) {
    let img, lens, result, cx, cy;
    img = document.getElementById(imgID);
    result = document.getElementById("my-result");
    lens = document.querySelector(".img-zoom-lens");
    cx = result.offsetWidth / lens.offsetWidth;
    cy = result.offsetHeight / lens.offsetHeight;
    result.style.backgroundImage = "url('" + img.src + "')";
    result.style.backgroundSize = (img.width * cx) + "px " + (img.height * cy) + "px";
    lens.addEventListener("mousemove", moveLens);
    img.addEventListener("mousemove", moveLens);
    lens.addEventListener("touchmove", moveLens);
    img.addEventListener("touchmove", moveLens);
    function moveLens(e) {
        let pos, x, y;
        e.preventDefault();
        pos = getCursorPos(e);
        x = pos.x - (lens.offsetWidth / 2);
        y = pos.y - (lens.offsetHeight / 2);
        if (x > img.width - lens.offsetWidth) {x = img.width - lens.offsetWidth;}
        if (x < 0) {x = 0;}
        if (y > img.height - lens.offsetHeight) {y = img.height - lens.offsetHeight;}
        if (y < 0) {y = 0;}
        lens.style.left = x + "px";
        lens.style.top = y + "px";
        result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "px";
    }
    function getCursorPos(e) {
        let a, x = 0, y = 0;
        e = e || window.event;
        a = img.getBoundingClientRect();
        x = e.pageX - a.left;
        y = e.pageY - a.top;
        x = x - window.pageXOffset;
        y = y - window.pageYOffset;
        return {x : x, y : y};
    }
}
// Function to change Images
(function () {
  let originalImg = document.querySelector("#my-image");
  let galleryImg = document.querySelector(".img-gallery").children;
  for(let i = 0; i < galleryImg.length; i++) {
    galleryImg[i].onclick = function() {
      originalImg.setAttribute("src", this.getAttribute("src"));
      imageZoom("my-image");
    };
  }
})();
* {
  box-sizing: border-box;
  font-family: sans-serif;
}
.img-container {
  position: relative;
  display: flex;
  justify-content: space-between;
}
.img-zoom-lens {
  position: absolute;
  border: 3px solid rgb(0, 126, 255);
  background-color: rgba(0, 126, 255, .2);
  width: 40px;
  height: 40px;
}
#my-image {
  max-width: 50%;
  height: 300px;
}
.img-zoom-result {
  border: 1px solid #f1f1f1;
  width: 300px;
  height: 300px;
}
.img-gallery {
  margin: 16px 0;
}
.img-gallery img {
  display: inline-block;
  cursor: pointer;
  width: 110px;
  height: 110px;
  border: 1px solid #ccc;
  padding: 4px;
  margin-right: 8px;
}
.img-gallery img:active {
  box-shadow: 0 0 0.1rem 0.1rem rgba(38,143,255,.5);
}
.img-gallery img:focus {
  box-shadow: 0 0 0.1rem 0.1rem rgba(38,143,255,.5);
}
<h1>Create an Image Zoom</h1>
<div class="img-container">
  <div class="img-zoom-lens"></div>
  <img id="my-image" src="https://parrot-tutorial.com/images/carousel_red3.jpg">
  <div id="my-result" class="img-zoom-result"></div>
</div>
<p>Choose more images:</p>
<div class="img-gallery">
    <img src="https://parrot-tutorial.com/images/avatar.jpg">
    <img src="https://parrot-tutorial.com/images/bottleship.jpg">
    <img src="https://parrot-tutorial.com/images/toxic.jpg">
</div>

参考:创建图像缩放