摘要：
最近弄PC端的需求时，要求在layui技术下实现鼠标滚动图片的放大缩小的功能！下面来总结一下不同框架剩下这功能！
layui:
看了一下layui文档，其实这有自带的组件的！但是又版本要求的!并且layui的官方文档是不维护的了！记得使用最新的版本！
layui.use(['table', "util"]function () {
var $ = layui.jquery;
var util = layui.util;
util.event('zoom', function(obj){
var oImg = document.getElementById('solo_pic');
var scale = obj.deltaY > 0 ? 1.1 : 0.9;
var width = oImg.width * scale;
var height = oImg.height * scale;
if (width > 500 || width < 10) return;
oImg.width = width;
oImg.height = height;
});
})
jquery:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title></title>
<link rel="stylesheet" href="">
<script src="../static/js/jquery-1.11.1.min.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
$(function() {
function zoomImg(o) {
var zoom = parseInt(o.style.zoom, 10) || 100;
zoom += event.wheelDelta / 12; //可适合修改
if (zoom > 0) o.style.zoom = zoom + '%';
}
$(document).ready(function() {
$("img").bind("mousewheel",
function() {
zoomImg(this);
return false;
});
});
})
</script>
</head>
<body>
<center>
<img src="../static/img/111.jpg" border="1px" />
</center>
</body>
</html>
添加遮罩层：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title></title>
<link rel="stylesheet" href="">
<script src="../static/js/jquery-1.11.1.min.js" type="text/javascript" charset="utf-8"></script>
<style>
/*************图片预览************/
#outerdiv {
position: fixed;
top: 0;
left: 0;
background: rgba(0, 0, 0, 0.7);
z-index: 2;
width: 100%;
height: 100%;
display: none;
}
#innerdiv {
position: absolute;
}
#bigimg {
border: 5px solid #fff;
cursor: pointer;
}
</style>
<script type="text/javascript">
$(function() {
function zoomImg(o) {
var zoom = parseInt(o.style.zoom, 10) || 100;
zoom += event.wheelDelta / 12; //可适合修改
if (zoom > 0) o.style.zoom = zoom + '%';
}
$(document).ready(function() {
$("img").bind("mousewheel",
function() {
zoomImg(this);
return false;
});
});
})
</script>
</head>
<body>
<center>
<img id="img" src="../static/img/111.jpg" border="1px" @click="bigimg()" />
</center>
<div id="outerdiv">
<div id="innerdiv">
<img id="bigimg" src="" onmousewheel="bigimg(this)" />
</div>
</div>
<script>
$(`#img`).click(function() {
var _this = $(this); //将当前的img元素作为_this传入函数
imgShow("#outerdiv", "#innerdiv", "#bigimg", _this);
})
// 图片缩放
function bigimg(obj) {
// alert(parseInt(obj.style.zoom, 10));
//obj是一个对象，初始时obj并没有zoom属性，所以给zoom赋值为100；
var zoom = parseInt(obj.style.zoom, 10) || 100;
//每次滚动鼠标时，改变zoom的大小
//event.wheelDelta有两个值，120，-120，取值情况取决于滚动鼠标的方向；
zoom += event.wheelDelta / 12; //每次滚动加减10
if (zoom > 0)
obj.style.zoom = zoom + '%'; //更改后的zoom赋值给obj
return false;
}
// 预览图片
function imgShow(outerdiv, innerdiv, bigimg, _this) {
var src = _this.attr("src"); //获取当前点击的pimg元素中的src属性
$(bigimg).attr("src", src); //设置#bigimg元素的src属性
/*获取当前点击图片的真实大小，并显示弹出层及大图*/
$("<img />").attr("src", src).load(function() {
var windowW = $(window).width(); //获取当前窗口宽度
var windowH = $(window).height(); //获取当前窗口高度
var realWidth = this.width; //获取图片真实宽度
var realHeight = this.height; //获取图片真实高度
var imgWidth, imgHeight;
var scale = 0.8; //缩放尺寸，当图片真实宽度和高度大于窗口宽度和高度时进行缩放
if (realHeight > windowH * scale) { //判断图片高度
imgHeight = windowH * scale; //如大于窗口高度，图片高度进行缩放
imgWidth = imgHeight / realHeight * realWidth; //等比例缩放宽度
if (imgWidth > windowW * scale) { //如宽度扔大于窗口宽度
imgWidth = windowW * scale; //再对宽度进行缩放
}
} else if (realWidth > windowW * scale) { //如图片高度合适，判断图片宽度
imgWidth = windowW * scale; //如大于窗口宽度，图片宽度进行缩放
imgHeight = imgWidth / realWidth * realHeight; //等比例缩放高度
} else { //如果图片真实高度和宽度都符合要求，高宽不变
imgWidth = realWidth;
imgHeight = realHeight;
}
$(bigimg).css("width", imgWidth); //以最终的宽度对图片缩放
var w = (windowW - imgWidth) / 2; //计算图片与窗口左边距
var h = (windowH - imgHeight) / 2; //计算图片与窗口上边距
$(innerdiv).css({ "top": h, "left": w }); //设置#innerdiv的top和left属性
$(outerdiv).fadeIn("fast"); //淡入显示#outerdiv及.pimg
});
$(outerdiv).click(function() { //再次点击淡出消失弹出层
$(this).fadeOut("fast");
});
}
</script>
</body>
</html>
为每个包含图片div元素附加了一个滚轮事件监听器，当用户在这些元素上滚动滚轮时，调用zoomImage函数进行放大/缩小操作。
在zoomImage函数内部，通过$(this).find('img')选择器找到了当前元素内img元素，接下来从滚轮事件中获取了用户的滚动方向，然后计算出当前图片的放大/缩小后的宽度和高度，并将其重新赋值给了图片元素。 注意在这个代码中我们同时监听了mousewheel和DOMMouseScroll`这两种不同浏览器的滚轮事件，以保证代码能够在不同的浏览器中正常运行。
$(document).ready(function() {
function zoomImage(event) {
event.preventDefault();
var image = $(this).find('img');
var delta = event.originalEvent.deltaY || event.originalEvent.detail || event.originalEvent.wheelDelta;
var zoom = delta > 0 ? -0.2 : 0.2;
var newWidth = image.width() + (image.width() * zoom);
var newHeight = image.height() + (image.height() * zoom);
image.width(newWidth).height(newHeight);
}
$('div.image-container').on('mousewheel DOMMouseScroll', zoomImage);
});
Vue，JS实现图片鼠标拖拽，滚轮放大缩小:
<template>
<div>
<img :src="src" :alt="alt" @click.stop="open()" :width="width" :height="height" title="点击查看图片"
:id="'vc-imgself-img-'+attach">
<div class="full-img" v-show="show" @contextmenu.prevent.stop="clearStyle">
<img :src="currentImageSrc" alt="" class="img-state" :alt="alt || ''" @mousewheel="bigimg(this)" id="image" draggable="false"
@mousedown.prevent="dropImage" style="position:fixed">
<div class="btns row">
<button type="button" name="button" class="btn btn-primary" @click.stop="leftRevolve()">向左旋转</button>
<button type="button" name="button" class="btn btn-primary" @click.stop="rightRevolve()">向右旋转</button>
<button type="button" name="button" class="btn btn-primary" @click.stop="close()">关闭</button>
<button type="button" name="button" class="btn btn-primary" @click.stop="previousPage()">上一页</button>
<button type="button" name="button" class="btn btn-primary" @click.stop="nextPage()">下一页</button>
</div>
</div>
</div>
</template>
<script>
import $ from 'jquery'
export default {
props: {
src: {
type: String
},
width: {
default: 60
},
height: {
default: 60
},
alt: {
default: '图片加载失败'
},
attach: {
type: String,
default: 'name'
},
list: {
type: Array,
default: []
}
},
data() {
return {
show: false,
deg: 0,
odiv: null,
powerw: 1.0,
container:null,
positionX: null,
positionY: null,
powerh: 1.0,
currentImageSrc:this.src
}
},
ready(){
const elementsToMount = document.getElementsByClassName("full-img");
this.container = document.createElement('div');
this.container.style.height = '0px'
// 将要挂载的元素放入新创建的 div中
for (let i = 0; i < elementsToMount.length; i++) {
this.container.appendChild(elementsToMount[i]);
}
// 将新创建的 div 挂载到 body 上
document.body.appendChild(this.container);
},
beforeDestroy(){
// 销毁挂载的
if (this.container && this.container.parentNode) {
this.container.parentNode.removeChild(this.container);
}
},
methods: {
nextPage() {
console.log(this.list)
//当前图片，是最后一张图片
if (this.currentImageSrc=== this.list[this.list.length - 1].f_overall_path) {
this.currentImageSrc= this.list[0].f_overall_path
} else {
for (let i = 0; i < this.list.length; i++) {
if (this.currentImageSrc=== this.list[i].f_overall_path) {
this.currentImageSrc= this.list[i + 1].f_overall_path
break
}
}
}
},
previousPage() {
console.log(this.list)
//当前图片，是第一张图片
if (this.currentImageSrc === this.list[0].f_overall_path) {
this.currentImageSrc= this.list[this.list.length - 1].f_overall_path
} else {
for (let i = 0; i < this.list.length; i++) {
if (this.currentImageSrc=== this.list[i].f_overall_path) {
this.currentImageSrc= this.list[i - 1].f_overall_path
break
}
}
}
},
clearStyle(e){
if (e === null) {
return
}
this.odiv = document.getElementById('image')
this.odiv.style.left = 500 + 'px';
this.odiv.style.top = -150 + 'px';
},
bigimg() {
if (event.wheelDelta > 0) {
this.powerh = this.powerh * 1.15
this.powerw = 1.15 * this.powerw
} else {
this.powerh = this.powerh * 0.85
this.powerw = 0.85 * this.powerw
}
this.imgState()
},
dropImage(e) {
if (e === null) {
return
}
this.odiv = e.target;
let disX = e.clientX - this.odiv.offsetLeft;
let disY = e.clientY - this.odiv.offsetTop;
document.onmousemove = (e) => {
let left = e.clientX - disX;
let top = e.clientY - disY;
this.positionX = top;
this.positionY = left;
this.odiv.style.left = left + 'px';
this.odiv.style.top = top + 'px';
};
document.onmouseup = (e) => {
document.onmousemove = null;
document.onmouseup = null;
};
},
open() {
this.deg = 0
this.powerw = 0.7
this.powerh = 0.8
$('.full-img').css({
'transform': 'rotate(' + this.deg + 'deg) scale(' + this.powerh + ' ,' + this.powerw + ')'
})
$('.container').css({
'opacity': '1'
})
this.show = true
},
close() {
this.show = false
},
leftRevolve() {
//tag
this.deg -= 90
this.imgState()
},
rightRevolve() {
//tag
this.deg += 90
this.imgState()
},
imgState() {
$('.img-state').css({
'transform': 'rotate(' + this.deg + 'deg) scale(' + this.powerh + ' ,' + this.powerw + ')'
})
}
},
}
</script>
<style media="screen" scoped>
.full-img {
position: fixed;
width: 100%;
/*height: 1000px;*/
overflow: hidden;
top: 0;
bottom: 0;
left: 0;
right: 0;
z-index: 1070;
opacity: 1;
background: rgba(0, 0, 0, 0.8);
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
color: #fff;
}
.btns {
position: fixed;
bottom: 100px;
height: auto;
}
.btns button {
margin-right: 20px;
}
.img-state {
}
</style>
调用组件:
<img-self-plus :width="120" :height="160" :src="row.url"></img-self-plus><
vue插件实现：
npm install vue-directive-zoom --save
<template>
<div v-zoom:2="zoomOptions">
<img src="path/to/your/image.jpg" alt="Zoomable Image">
</div>
</template>
<script>
import Vue from 'vue';
import VueDirectiveZoom from 'vue-directive-zoom';
Vue.use(VueDirectiveZoom);
export default {
data() {
return {
zoomOptions: {
mouseWheel: true, // 开启鼠标滚轮缩放
zoomMax: 5, // 最大缩放比例
zoomMin: 1, // 最小缩放比例
zoomStart: 1 // 初始缩放比例
}
};
}
};
</script>
v-zoom:2指令用于放大图片，你可以通过调整zoomOptions中的参数来控制缩放的行为，如是否启用鼠标滚轮缩放，以及设置最大和最小缩放比例等。
请注意，vue-directive-zoom库可能不是最新的，并且可能不支持Vue 3。如果你使用的是Vue 3，可能需要寻找其他的解决方案。
react:
React中实现鼠标滚动来放大缩小图片，可以通过监听wheel事件来实现。
import React, { useState, useRef } from 'react';
import './App.css';
function App() {
const [scale, setScale] = useState(1);
const imageRef = useRef(null);
const handleWheel = (e) => {
e.preventDefault();
const newScale = e.deltaY > 0 ? scale * 1.1 : scale / 1.1;
setScale(newScale);
};
return (
<div className="App">
<div
className="image-container"
ref={imageRef}
style={{ transform: `scale(${scale})` }}
onWheel={handleWheel}
>
<img src="path_to_your_image.jpg" alt="Zoomable Image" />
</div>
</div>
);
}
export default App;
我们使用了React的useState钩子来跟踪图片的缩放比例，并使用useRef钩子来获取对图片容器的引用。handleWheel函数会在鼠标滚轮滚动时被调用，并根据滚动的方向计算新的缩放比例。然后，我们通过设置容器的transform样式来应用缩放效果。
请确保在CSS中设置.image-container的overflow属性为hidden，以防止缩放后的图片溢出容器。
/* App.css */
.image-container {
overflow: hidden;
display: inline-block;
/* other styles */
}
