htmledit_views">
1、模态框(弹出框)
（1）、需求：
- 点击弹出层，会弹出模态框，并且显示灰色半透明的遮挡层
- 点击关闭按钮，可以关闭模态框，并且同时关闭半透明遮挡层
- 鼠标放在模态框最上面一行，可以按住鼠标拖拽模态框在页面中移动
- 鼠标松开，可以停止拖动模态框移动
思路：
- 点击弹出层，模态框和遮挡层就会显示出来 display:block
- 点击关闭按钮，模态框和遮罩层会隐藏起来 display:none
- 在页面中拖拽的原理：鼠标按下并且移动，之后松开鼠标
- 触发事件是鼠标按下mousedown，鼠标移动mousemove 鼠标松开 mouseup
- 拖拽过程，鼠标移动过程中，获得最新的值赋值给模态框的left和top值，这样模态框就可以跟着鼠标走了
- 鼠标按下触发的事件源是h2
- 鼠标的坐标减去鼠标内的坐标，才是模态框真正的位置
- 鼠标按下，我们要得到鼠标在盒子的坐标
- 鼠标移动，就让模态框的坐标设置为：鼠标坐标减去盒子坐标即可，注意移动时间写到按下
- 鼠标松开，就停止拖拽，可以让鼠标移动事件解除
（2）、es5
html" title=javascript>javascript"><!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8" /><title>Document</title><style>* {margin: 0;padding: 0;}h1 {cursor: pointer;margin: 50px auto;}/* 模态框 */.modal-box {display: none;width: 400px;height: 300px;background-color: #bfa;position: absolute;left: 50%;top: 50%;transform: translate(-50%, -50%);z-index: 99;}button {position: absolute;right: 50px;top: 30px;width: 80px;line-height: 40px;}/* 遮罩层 */.bg {display: none;position: absolute;width: 100%;height: 100%;left: 0;top: 0;background-color: #000;opacity: 0.3;}.title {background-color: aqua;line-height: 60px;}</style></head><body><h1>点击，弹出模态框</h1><!-- 弹出框 --><div class="modal-box"><button>关闭</button><h2 class="title">我是一个可爱的模态框·····</h2></div><!-- 遮罩层 --><div class="bg"></div><!-- js --><script>// 1、获取元素var h1 = document.querySelector("h1");var modalBox = document.querySelector(".modal-box");var btn = document.querySelector("button");var bg = document.querySelector(".bg");var title = document.querySelector(".title");// 2、点击显示，隐藏模态框h1.onclick = function () {modalBox.style.display = "block";bg.style.display = "block";};btn.onclick = function () {modalBox.style.display = "none";bg.style.display = "none";};// 3、开始拖拽模态框//（1）、当我们鼠标按下，就获得鼠标在盒子内的坐标title.addEventListener("mousedown", function (e) {var x = e.pageX - modalBox.offsetLeft;var y = e.pageY - modalBox.offsetTop;// (2)、鼠标移动的时候，把鼠标在页面中的坐标，减去鼠标在盒子内的坐标// 就是不断的求modalBox.offsetLeft ，modalBox.offsetTop// 不能直接用offset// 直接用offset得到的是盒子本来的坐标，盒子要动起来，才能改变offset的值，// 当我们是想要先改变offset然后用他来改变盒子的位置，所以不能直接用offset// 而是用鼠标的位置来动态的输入offsetfunction move(e) {modalBox.style.left = e.pageX - x + "px";modalBox.style.top = e.pageY - y + "px";// 这样设置，会导致，初始化移动时，就把鼠标的位置，赋值给盒子的中心，有个跳跃的过程// modalBox.style.left = e.pageX + "px";// modalBox.style.top = e.pageY + "px";// modalBox.offsetLeft 是固定的值，不会变化的，需要先动盒子才能得到新的modalBox.offsetLeft// modalBox.style.left = modalBox.offsetLeft + "px";// modalBox.style.top = modalBox.offsetTop + "px";}document.addEventListener("mousemove", move);// （3）、鼠标弹起，就让鼠标移动事件移除document.addEventListener("mouseup", function () {document.removeEventListener("mousemove", move);});});</script></body>
</html>（3）、es6
html" title=javascript>javascript"><script>let that;class Modal {constructor() {that = this;// 获取元素this.clickH1 = document.getElementById("clickH1");this.btn = document.getElementById("btn");this.modalBox = document.querySelector(".modal-box");this.bg = document.querySelector(".bg");this.title = document.querySelector(".title");// 调用监听函数this.event();}// 监听函数event() {this.clickH1.addEventListener("click", this.clickH1Fun);this.btn.addEventListener("click", this.btnFun);this.title.addEventListener("mousedown", this.titleFun);}// 点击出现遮罩层clickH1Fun() {that.bg.style.display = "block";that.modalBox.style.display = "block";}// 点击关闭按钮btnFun() {that.bg.style.display = "none";that.modalBox.style.display = "none";}//鼠标按下titletitleFun(e) {// 获取鼠标在模态框中的位置方式一let x = e.offsetX;let y = e.offsetY;// 获取鼠标在模态框中的位置方式二// let x = e.pageX - that.modalBox.offsetLeft;// let y = e.pageY - that.modalBox.offsetTop;console.log(x, y);document.addEventListener("mousemove", moveFun);function moveFun(e) {// console.log(111);let left = e.pageX - x;let right = e.pageY - y;that.modalBox.style.left = left + "px";that.modalBox.style.top = right + "px";that.modalBox.style.margin = 0; //left 值变化，由于过度约束，需要重新设置margin// that.modalBox.style.transform='translate(0%, 0%)'//left 值变化，由于过度约束，需要重新设置偏移量}document.addEventListener("mouseup", upFun);function upFun() {document.removeEventListener("mousemove", moveFun);}}}new Modal();</script>2、放大镜
（1）html/css
-
- 整个案例可以分为三个功能模块
- 鼠标经过小图片盒子，黄色的遮罩层和大图片盒子显示，离开隐藏2个盒子功能
- 黄色的遮挡层跟随鼠标移动功能
- 移动黄色遮挡层，大图片跟随移动功能
html" title=javascript>javascript"><!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8" /><title>放大镜案例</title><style>* {margin: 0;padding: 0;}/* 小图 */.camera {width: 300px;height: 300px;position: relative;border: 1px solid black;}.cameraImg img {width: 300px;height: 300px;}/* 遮罩层 */.zoom {width: 100px;height: 100px;background-color: #ccc;opacity: 0.8;position: absolute;top: 0px;left: 0px;}/* 大图 */.bDiv {width: 500px;height: 500px;background-color: bisque;position: absolute;left: 350px;top: 0;overflow: hidden;}.bImg {position: absolute;top: 0;left: 0;}</style></head><body><div class="camera"><!-- 小图 --><div class="cameraImg"><img src="./img0.jpg" alt="" /></div><!-- 放大镜 --><div class="zoom"></div><!-- 大图 --><div class="bDiv"><img src="./img1.jpg" alt="" class="bImg" /></div></div><!-- 引入js --><script src="./放大镜.js"></script></body>
</html>（2）、es5 js
html" title=javascript>javascript">window.onload = function () {var camera = document.querySelector(".camera");var zoom = document.querySelector(".zoom");var bDiv = document.querySelector(".bDiv");var bImg = document.querySelector(".bImg");// 1:给camera绑定鼠标移入移除事件，让鼠标移除时，放大镜跟展示页都消失camera.onmouseenter = function () {zoom.style.display = "block";bDiv.style.display = "block";};camera.onmouseleave = function () {// zoom.style.display = "none";// bDiv.style.display = "none";};// 2:设置放大镜zoom能跟着鼠标移动，并设置范围活动camera.onmousemove = function (event) {//2.1 获得鼠标的页面坐标x,yvar x = event.pageX;var y = event.pageY;// console.log(x, y);//2.2 获取图相对于页面的左边，上边相对距离var offsetX = camera.offsetLeft;var offsetY = camera.offsetTop;// console.log(offsetX, offsetY);// 2.3 获取遮挡层的宽度跟高度var zoomW = zoom.offsetWidth;var zoomH = zoom.offsetHeight;// console.log(zoomW,zoomH);// 2.4 计算遮挡物的xy坐标var left = x - offsetX - zoomW / 2;var top = y - offsetY - zoomH / 2;// 2.5 设置判断left top的限制值/* 遮盖物的最大移动距离，父元素camera的宽度减去遮盖物的宽度(300-100) */if (left >= 200) {left = 200;}if (left <= 0) {left = 0;}if (top >= 200) {top = 200;}if (top <= 0) {top = 0;}//2.6 将宽高赋值给放大镜zoom.style.left = left + "px";zoom.style.top = top + "px";/* 3、根据比例移动大图 遮罩层的移动距离 /遮罩层最大移动距离 = 大图片移动距离/大图片最大移动距离根据上面的等式，可以演算出大图片的移动距离=（遮罩层的移动距离 /遮罩层最大移动距离）*大图片最大移动距离 *///3.1 计算大图在大盒子里移动的最大距离/* 大图的宽度，减去bDiv框子的宽度*/var bImgMw = bImg.offsetWidth - bDiv.offsetWidth;var bImgMh = bImg.offsetHeight - bDiv.offsetHeight;// console.log(bDiv.offsetWidth);// 3.2 根据比例移动大图var bX = (left / 200) * bImgMw;var bY = (top / 200) * bImgMh;// 3.3 将bX，bY赋值给大图的宽高bImg.style.left = -bX + "px";bImg.style.top = -bY + "px";};
};（3）、es6.js
html" title=javascript>javascript">window.onload = function () {var that;class Camera {constructor() {// 保存thisthat = this;// 获取整个盒子this.camera = document.querySelector(".camera");this.zoom = document.querySelector(".zoom");this.bDiv = document.querySelector(".bDiv");this.bImg = document.querySelector(".bImg");//初始化放大镜的位置left，topthis.left = 0;this.top = 0;//初始化监听函数this.addevent();}// 监听事件addevent() {//1.1、移入显示放大镜，移出隐藏放大镜this.camera.addEventListener("mouseenter", that.showZoom);this.camera.addEventListener("mouseleave", that.hiddZoom);//2、移入，放大镜随着鼠标移动this.camera.addEventListener("mousemove", that.zoomMove);//2、放大镜移动，大图也随着移动this.camera.addEventListener("mousemove", that.bDivMove);}//1.2 鼠标移入，显示放大镜及大图showZoom() {that.zoom.style.display = "block";that.bDiv.style.display = "block";}hiddZoom() {that.zoom.style.display = "none";that.bDiv.style.display = "none";}// 1.2 放大镜随着鼠标移动zoomMove(e) {// 如果直接赋值，会出现闪烁，由于只有鼠标动了，才会获取到offseX/Y的值，移动之前为0// let left = e.offsetX;// let top = e.offsetY;// （1）、鼠标在页面中的坐标var x = e.pageX;var y = e.pageY;//(2)、大盒子camera在在页面中的位置var offsetLeft = that.camera.offsetLeft;var offsetTop = that.camera.offsetTop;//（3）、计算zoom的大小var zoomWidth = that.zoom.offsetWidth;var zoomHeight = that.zoom.offsetHeight;//（4）、计算盒子中鼠标的位置that.left = x - offsetLeft - zoomWidth / 2;that.top = y - offsetTop - zoomHeight / 2;//(5)、限制放大镜的移动范围，camera-zoomif (that.left <= 0) {that.left = 0;}if (that.left >= 200) {that.left = 200;}if (that.top <= 0) {that.top = 0;}if (that.top >= 200) {that.top = 200;}//(6)、将计算出的鼠标位置赋值给zoomthat.zoom.style.left = that.left + "px";that.zoom.style.top = that.top + "px";}// 3、放大镜移动，大图也随着移动// zoom移动距离/zoom最大移动距离 = 大图移动距离/大图最大移动距离bDivMove() {// 计算大图的最大移动距离 大图-大图盒子大小var bimgMaxWidth = that.bImg.offsetWidth - that.bDiv.offsetWidth;var bimgMaxHeight = that.bImg.offsetHeight - that.bDiv.offsetHeight;// 计算大图移动距离（zoom移动距离/zoom最大移动距离）*大图最大移动距离var bimgLeft = (that.left / 200) * bimgMaxWidth;var bimgTop = (that.top / 200) * bimgMaxHeight;that.bImg.style.left = -bimgLeft + "px";that.bImg.style.top = -bimgTop + "px";}}new Camera();
};3、京东侧边导航条
需求：
-
- 原先侧边栏是绝对定位
- 当页面滚动到一定位置，侧边栏改为固定定位
- 页面继续滚动，会让返回顶部显示出来
思路：
-
- 需要用到页面滚动事件scroll，因为是页面滚动，所以事件源是document
- 滚动到某个位置，就是判断页面被卷去的上部值
- 页面被卷去的头部：可以通过window.pageYOffset获得，如果是被卷去的左侧window.pageXOffset
- 注意：元素被卷去的头部是element.scrollTop,如果是页面被卷去的头部则是window.pageYOffset
html" title=javascript>javascript"><!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8" /><title>侧边栏案例</title><style>* {padding: 0;margin: 0;}header,footer {width: 1000px;height: 200px;background-color: pink;margin: 0 auto;}main {width: 1000px;height: 800px;background-color: #bfa;margin: 0 auto;}nav {width: 60px;height: 200px;background-color: blue;position: absolute;right: 0;top: 250px;line-height: 30px;}span {display: block;width: 60px;height: 60px;background-color: red;margin-top: 140px;text-align: center;display: none;}</style></head><body><header>头部</header><nav><span>返回 <br />顶部</span></nav><main>主体</main><footer>底部</footer><script>// 1、获取元素var span = document.querySelector("span");var nav = document.querySelector("nav");var main = document.querySelector("main");// 主体以上被卷去的距离var mainTop = main.offsetTop;// 侧边导航以上被卷去的距离var navTop = nav.offsetTop;console.log(navTop);// 2、页面滚动事件 scrolldocument.addEventListener("scroll", function () {// window.pageYOffset 获取页面被滚去的距离// 3、判断距离，变化定位if (window.pageYOffset >= mainTop) {// 3.1将定位改成固定定位nav.style.position = "fixed";// 3.2 改成固定定位后，会有跳动，需要重新设置定位的top值,否则还是原值nav.style.top = navTop - mainTop + "px";// 3.3 出现返回顶部字样span.style.display = "block";} else {nav.style.position = "absolute";nav.style.top = "300px";span.style.display = "none";}});</script></body>
</html>4、轮播图
（1）、搭建轮播图的结构
html" title=javascript>javascript"><!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8" /><title>轮播图结构</title><!-- <script src="../js/tools.js"></script> --><script src="../js/animation.js"></script><script src="./01.轮播图.js"></script><style>* {padding: 0;margin: 0;list-style: none;text-decoration: none;}#outer {width: 590px;height: 470px;border: 10px solid red;margin: 50px auto;position: relative;overflow: hidden;}#outer > ul {width: 500%;position: absolute;left: 0;top: 0;}#outer > ul > li {float: left;}.dot {position: absolute;bottom: 30px;left: 50%;transform: translate(-50%, -50%);}.dot > a {display: inline-block;width: 15px;height: 15px;border-radius: 50%;background-color: #999;margin: 0 5px;}.dot > .active,.dot > a:hover {background-color: orange;}.prev,.next {width: 40px;height: 40px;background-color: rgba(0, 0, 0, 0.4);text-align: center;position: absolute;font-size: 30px;color: #999;/* 隐藏左右按钮 */display: none;}.prev > a,.next > a {color: #fff;}.prev {left: 10px;top: 42%;}.next {right: 10px;top: 42%;}</style></head><body><div id="outer"><!-- 图片部分 --><ul><li><a href="#"><img src="./img/1.jpg" alt="" /></a></li><li><a href="#"><img src="./img/2.jpg" alt="" /></a></li><li><a href="#"><img src="./img/3.jpg" alt="" /></a></li><li><a href="#"><img src="./img/4.jpg" alt="" /></a></li><!-- <li><a href="#"><img src="./img/1.jpg" alt="" /></a></li> --></ul><!-- 导航点 class="active"--><div class="dot"><!-- <a href="#" ></a><a href="#"></a><a href="#"></a><a href="#"></a> --></div><!-- 左右导航 --><ol class="prevNext"><li class="prev"><a href="#"> <</a></li><li class="next"><a href="#">></a></li></ol></div></body>
</html>（2）、es5写法
功能需求：
- 鼠标经过轮播图模块，左右按钮显示，离开隐藏左右按钮
- 点击右侧按钮一次，图片往左播放一张，以此类推，左侧按钮同理
- 图片播放的同时，下面的小圆圈模块跟随一起变化
- 点击小圆圈，可以播放相应图片
- 鼠标不经过轮播图，轮播图也会自动播放图片
- 鼠标经过，轮播图模块，自动播放停止
es5写法
html" title=javascript>javascript">window.addEventListener("load", function () {var prev = this.document.querySelector(".prev");var next = this.document.querySelector(".next");var outer = this.document.querySelector("#outer");//需求1 鼠标移入，左右按钮出现隐藏outer.addEventListener("mouseenter", function () {prev.style.display = "block";next.style.display = "block";});outer.addEventListener("mouseleave", function () {prev.style.display = "none";next.style.display = "none";});//需求2 动态生成pot，小圆圈// 2.1、获取元素var ulL = outer.querySelector("ul");var dot = outer.querySelector(".dot");for (var i = 0; i < ulL.children.length; i++) {// 2.2、动态的创建a标签var a = this.document.createElement("a");// 给a添加索引，方便下面计算点击圆圈，移动图片a.setAttribute("index", i);// 2.3 插入节点dot.appendChild(a);}// 2.4 给第一个小点，设置选中样式dot.children[0].className = "active";//需求3 给点击的小圆圈加上类名 active 排他思想var as = dot.querySelectorAll("a");for (var i = 0; i < as.length; i++) {as[i].addEventListener("click", function () {for (var j = 0; j < as.length; j++) {dot.children[j].className = "";}this.className = "active";//需求4 点击小圆圈，移动图片 move(obj, attr, target, speed, callback)//4.1 获取点击a的索引，这个索引是创建a时添加的，用来表示每个avar index = this.getAttribute("index");// 4.2 ulL的移动距离，小圆圈的索引号*图片的宽度animation(ulL, -index * 590);// move(ulL, "left", -index * 590, 10);// 获取到index后，需要同步赋值给下面的num跟current// 以便可以同步小圆点，跟点击下一张的变化num = index;current = index;});}// 克隆第一张图片,不在结构里加// 循环生成小圆点的时候，还没有克隆这个图片。所有不会自动生成的小圆圈var firstImg = ulL.children[0].cloneNode(true);ulL.appendChild(firstImg);//需求5 点击左右按钮，实现上下一张切换var num = 0;var current = 0; //用来标记小圆圈next.addEventListener("click", function () {//无缝滚动 如果走到了最后一张图片，此时我们的ul要快速复原left改为0if (num >= ulL.children.length - 1) {ulL.style.left = 0;num = 0;}num++;animation(ulL, -num * 590);// move(ulL, "left", -num * 590, 20);// 点击右侧按钮，小圆圈跟着跳动current++;// 如果curent的数值跟小圆圈的数量一样，走到了克隆的那张图片，要还原为0if (current == dot.children.length) {current = 0;}for (var i = 0; i < dot.children.length; i++) {dot.children[i].className = "";}dot.children[current].className = "active";});//需求6 左侧按钮的功能prev.addEventListener("click", function () {if (num == 0) {num = ulL.children.length - 1;ulL.style.left = -num * 590 + "px";}num--;animation(ulL, -num * 590);// move(ulL, "left", -num * 590, 20);// 点击右侧按钮，小圆圈跟着跳动current--;// 如果curent的数值跟小圆圈的数量一样，要还原为0if (current < 0) {current = dot.children.length - 1;}for (var i = 0; i < dot.children.length; i++) {dot.children[i].className = "";}dot.children[current].className = "active";});//需求7 自动播放功能var timer = setInterval(function () {// 手动调用点击事件next.click();}, 2000);//需求8 鼠标移入，自动播放停止outer.addEventListener("mouseenter", function () {clearInterval(timer);timer = null;});//需求9 鼠标移出，重新开启定时器outer.addEventListener("mouseleave", function () {timer = setInterval(function () {// 手动调用点击事件next.click();}, 2000);});
});（3）、es6写法
html" title=javascript>javascript">window.onload = function () {var that;class Swiper {constructor() {// 保存thisthat = this;// 1.1 获取对应元素this.prev = document.querySelector(".prev");this.next = document.querySelector(".next");this.outer = document.querySelector("#outer");//2.1 获取导航点父元素this.dot = document.querySelector(".dot");this.imgList = document.querySelector(".imgList");// 2.4 调用创建小圆点函数this.creatDot();// 3.1 获取图片导航小圆点this.dots = document.querySelectorAll(".dot a");// 4.1 用于标识当前的图片位置this.num = 0;this.current = 0; //用于标识当前小圆点的位置// 5、克隆轮播图第一张照片this.cloneFirstImg();// 调用监听函数this.addevent();}// 所有监听函数addevent() {console.log(this);// 1.2 监听鼠标是否移入this.outer.addEventListener("mouseenter", that.pervNextShow);this.outer.addEventListener("mouseleave", that.pervNextNode);// 3.3 监听是否点击了小圆点for (var i = 0; i < this.dots.length; i++) {// 保存i值，方便找对应的图片this.dots[i].index = i;// 默认第一个按钮为选中状态this.dots[0].className = "active";// 点击切换背景色this.dots[i].addEventListener("click", that.updatBackgroundColor);// 点击切换图片this.dots[i].addEventListener("click", that.updatImg);}// 4、点击nextthis.next.addEventListener("click", that.nextFun);// 5、点击prevthis.prev.addEventListener("click", that.prevFun);// 8、调用自动轮播函数this.timer = null; //定义标识定时器this.autoPlay();// 9、移入outer，暂停自动轮播this.outer.addEventListener("mouseenter", that.stopAutoPlay);// 10、移出outer，继续自动轮播this.outer.addEventListener("mouseleave", that.startAutoPlay);}// 所有功能函数// 注意函数中的this指向// 1.3 上下一张出现pervNextShow() {that.prev.style.display = "block";that.next.style.display = "block";}pervNextNode() {that.prev.style.display = "none";that.next.style.display = "none";}// 2、根据图片创建导航点creatDot() {var imgNum = this.imgList.children.length;for (var i = 0; i < imgNum; i++) {var a = `<a href="#" ></a>`;this.dot.insertAdjacentHTML("afterBegin", a);}}// 3.4 点击小圆点，切换颜色updatBackgroundColor(e) {// （1）、先解决默认行为，超链接跳转的问题e.preventDefault();// (2)、点击颜色切换for (var i = 0; i < that.dots.length; i++) {that.dots[i].className = "";}this.className = "active";}// 3.5 点击小圆点，切换图片updatImg() {// (3)、根据图片导航点的索引移动图片animation(that.imgList, -590 * this.index);}// 4、点击下一张，切换图片nextFun() {// 根据num的值，判断num是否++var len = that.imgList.children.length;if (that.num >= len - 1) {that.imgList.style.left = 0;that.num = 0;}that.num++;animation(that.imgList, -that.num * 590);// 点击下一张照片后，更换小圆点背景色that.current++;if (that.current == that.dots.length) that.current = 0;//调用更换小圆点颜色函数that.changeBackgroundColor();}// 5、为解决轮播图最后一张快速问题，多赋值一张照片cloneFirstImg() {var firstImg = that.imgList.children[0].cloneNode(true);that.imgList.appendChild(firstImg);}// 6、更换小圆点颜色changeBackgroundColor() {for (var i = 0; i < that.dots.length; i++) {that.dots[i].className = "";}that.dots[that.current].className = "active";}// 7、点击prev，上一张照片prevFun() {// 根据num的值，判断显示图片if (that.num == 0) {that.num = that.imgList.children.length - 1;that.imgList.style.left = -that.num * 590 + "px";}that.num--;animation(that.imgList, -that.num * 590);// 同步图片小圆点的背景色if (that.current <= 0) {that.current = that.dots.length;}that.current--;//调用更换小圆点颜色函数that.changeBackgroundColor();}// 8、自动轮播，每隔2s，调动一次next函数autoPlay() {that.timer = setInterval(function () {that.nextFun();}, 2000);}// 9、鼠标移入轮播图，停止自动轮播stopAutoPlay() {// console.log(that.timer);clearInterval(that.timer);that.timer = null;}// 10、鼠标移出轮播图，开始自动轮播startAutoPlay() {that.autoPlay();}}new Swiper();
};（4）、节流阀优化
防止轮播图按钮连续点击造成播放过快
节流阀目的，当上一个函数动画内容执行完毕，再去执行下一个函数动画，让事件无法连续触发
核心实现思路：利用回调函数，添加一个变量来控制，锁住函数和解锁函数
开始设置一个变量 var flag =true
if（flag）{ flag = false,do something} 关闭水龙头
利用回调函数动画执行完毕， falg=true 打开水龙头
html" title=javascript>javascript"> // 10、节流阀优化点击过快问题var flag = true;next.addEventListener("click", function () {if (flag) {flag = false; // 关闭水龙头//无缝滚动 如果走到了最后一张图片，此时我们的ul要快速复原left改为0if (num >= ulL.children.length - 1) {ulL.style.left = 0;num = 0;}num++;animation(ulL, -num * 590, function () {flag = true;});// move(ulL, "left", -num * 590, 20);// 点击右侧按钮，小圆圈跟着跳动current++;// 如果curent的数值跟小圆圈的数量一样，走到了克隆的那张图片，要还原为0if (current == dot.children.length) {current = 0;}for (var i = 0; i < dot.children.length; i++) {dot.children[i].className = "";}dot.children[current].className = "active";}});//需求6 左侧按钮的功能prev.addEventListener("click", function () {if (flag) {flag = false;if (num == 0) {num = ulL.children.length - 1;ulL.style.left = -num * 590 + "px";}num--;animation(ulL, -num * 590, function () {flag = true;});// move(ulL, "left", -num * 590, 20);// 点击右侧按钮，小圆圈跟着跳动current--;// 如果curent的数值跟小圆圈的数量一样，要还原为0if (current < 0) {current = dot.children.length - 1;}for (var i = 0; i < dot.children.length; i++) {dot.children[i].className = "";}dot.children[current].className = "active";}});
