javascript实现花样轮播效果
本文实例为大家分享了javascript实现花样轮播效果的两种实现方法,供大家参考,具体内容如下
第一种:简单的带按钮的轮播
介绍:左右按钮控制轮播,点击左按钮切换上一张图片,点击右按钮切换下一张
html如下:
<div class="box"> <div class="imgbox"> <a><img src="img/banner1.jpg" alt=""></a> <a><img src="img/banner2.jpg" alt=""></a> <a><img src="img/banner3.jpg" alt=""></a> <a><img src="img/banner4.jpg" alt=""></a> <a><img src="img/banner5.jpg" alt=""></a> </div> <div class="btns"> <input type="button" id="left" value="<<<"> <input type="button" id="right" value=">>>"> </div>
css如下:
.box{width: 1000px;height: 300px;margin: 20px auto;position: relative;overflow: hidden;} .box .imgbox{} .imgbox a{width: 1000px;height: 300px;position: absolute;left:1000px;top:0;} .imgbox a:nth-child(1){left:0;} .imgbox img{width: 1000px;height: 300px;} .btns input{width: 40px;height: 40px;position: absolute;top:130px;border: none;background: rgba(200,200,200,0.5);} #left{left:0;} #right{right: 0;}}
js如下:
class Banner{ constructor(){ this.left = document.getElementById("left"); this.right = document.getElementById("right"); this.c【本文由:日本cn2服务器 提供 转载请保留URL】hild = document.querySelectorAll(".imgbox a"); // 要进来的 this.iNow = 0; // 要走的 this.iPrev = this.child.length - 1; } init(){ var that = this; this.left.addEventListener("click",function(){ that.changeIndex(1); }) this.right.addEventListener("click",function(){ that.changeIndex(2); }) } changeIndex(direct){ if(direct == 1){ if(this.iNow == 0){ this.iNow = this.child.length-1; this.iPrev = 0; }else{ this.iNow--; this.iPrev = this.iNow + 1; } }else{ if(this.iNow == this.child.length-1){ this.iNow = 0; this.iPrev = this.child.length-1; }else{ this.iNow++; // 要走的索引永远是进来的索引-1 this.iPrev = this.iNow - 1; } } // 根据索引开始运动 this.move(direct); } move(direct){ if(direct == 1){ // iPrev走 // 从0,走到1000 this.child[this.iPrev].style.left = 0; move(this.child[this.iPrev],{left:1000}); // iNow进来 // 从-1000,进到0 this.child[this.iNow].style.left = -1000 + "px"; move(this.child[this.iNow],{left:0}); }else{ this.child[this.iPrev].style.left = 0; move(this.child[this.iPrev],{left:-1000}); this.child[this.iNow].style.left = 1000 + "px"; move(this.child[this.iNow],{left:0}); } } } var b = new Banner(); b.init();
第二种:自动轮播
介绍:两个左右按钮可以控制图片左右切换,下面带有数字的按钮,点击数字几,就可以切换到第几张,自动轮播的过程中,鼠标进入停止轮播,鼠标离开继续轮播
htm代码如下:
<div class="box"> <div class="imgbox"> <a><img src="../img/banner1.jpg" alt=""></a> <a><img src="../img/banner2.jpg" alt=""></a> <a><img src="../img/banner3.jpg" alt=""></a> <a><img src="../img/banner4.jpg" alt=""></a> <a><img src="../img/banner5.jpg" alt=""></a> </div> <div class="btns"> <input type="button" id="left" value="<<<"> <input type="button" id="right" value=">>>"> </div> <div class="list"> </div> </div>
css代码如下:
.box{width: 1000px;height: 300px;margin: 20px auto;position: relative;overflow: hidden;} .box .imgbox{} .imgbox a{width: 1000px;height: 300px;position: absolute;left:1000px;top:0;} .imgbox a:nth-child(1){left:0;} .imgbox img{width: 1000px;height: 300px;} .btns input{width: 40px;height: 40px;position: absolute;top:130px;border: none;background: rgba(200,200,200,0.5);} #left{left:0;} #right{right: 0;} .list{width: 1000px;height: 30px;position: absolute;left: 0;bottom: 0;display: flex;background: rgba(200,200,200,0.5);} .list span{flex: 1;line-height: 30px;text-align: center;border-left:solid 1px black;border-right: solid 1px black;} .list span.active{background: red;color: #fff;}
js代码如下:
class Banner{ constructor(){ this.left = document.getElementById("left"); this.right = document.getElementById("right"); this.child = document.querySelectorAll(".imgbox a"); this.list = document.querySelector(".list"); this.box = document.querySelector(".box"); this.iNow = 0; this.iPrev = this.child.length - 1; } init(){ var that = this; this.left.addEventListener("click",function(){ that.changeIndex(1); }) this.right.addEventListener("click",function(){ that.changeIndex(-1); }) // L3.事件委托绑定事件 this.list.onclick = function(eve){ var e = eve || window.event; var tar = e.target || e.srcElement; if(tar.tagName == "SPAN"){ // L4.触发事件时,执行改变索引,同时将点前点击的span传入 that.listChangeIndex(tar); } } } changeIndex(direct){ if(direct == 1){ if(this.iNow == 0){ this.iNow = this.child.length-1; this.iPrev = 0; }else{ this.iNow--; this.iPrev = this.iNow + 1; } }else{ if(this.iNow == this.child.length-1){ this.iNow = 0; this.iPrev = this.child.length-1; }else{ this.iNow++; this.iPrev = this.iNow - 1; } } this.move(direct); } move(direct){ // 根据左右按钮传入的状态:左1,右-1 // 利用乘法 // 改变不同按钮的方向问题 this.child[this.iPrev].style.left = 0; move(this.child[this.iPrev],{left:this.child[0].offsetWidth * direct}); this.child[this.iNow].style.left = -this.child[0].offsetWidth * direct + "px"; move(this.child[this.iNow],{left:0}); this.setActive(); } createList(){ // L1.创建对应图片数量的span,同时编号 var str = ``; for(var i=0;i<this.child.length;i++){ str += `<span index='${i}'>${i+1}</span>`; } this.list.innerHTML = str; // L2.设置默认的当前项 this.setActive(); } setActive(){ for(var i=0;i<this.list.children.length;i++){ this.list.children[i].className = ""; } this.list.children[this.iNow].className = "active"; } listChangeIndex(tar){ // L5.确定要走的索引和要进来的索引 // this.iNow 要走的 // 拿到点击的span的编号 要进来的 var index = parseInt(tar.getAttribute("index")); // console.log(this.iNow, index); // L6-1.判断方向 if(index > this.iNow){ // L7-1.向左运动 this.listMove(1,index); } // L6-2.判断方向 if(index < this.iNow){ // L7-2.向右运动 this.listMove(-1,index); } // L8.将当前点击的索引设置成下次要走的索引 this.iNow = index; // L9.根据修改之后的索引,设置当前项 this.setActive(); } listMove(direct,index){ // this.iNow走 // 从哪走,走到哪 this.child[this.iNow].style.left = 0; move(this.child[this.iNow],{left:-1000 * direct}) // index进来 // 从哪进来,进到哪s this.child[index].style.left = 1000 * direct + "px"; move(this.child[index],{left:0}); } autoPlay(){ var t = setInterval(()=>{ this.changeIndex(-1); },2000) this.box.onmouseover = function(){ clearInterval(t); } var that = this; this.box.onmouseout = function(){ t = setInterval(()=>{ that.changeIndex(-1); },2000) } // console.log(that); } } var b = new Banner(); b.init(); b.createList(); b.autoPlay();
两个案例 js 里面的move是一个缓冲运动的封装,代码如下:
function move(ele,obj,cb){ clearInterval(ele.t); ele.t = setInterval(() => { // 假设状态为:可以清除计时器 var i = true; // 因为在计时器中才开始使用到对象中的信息,所以在计时器中遍历 // 并提前换来的属性和目标变量 for(var attr in obj){ if(attr == "opacity"){ var iNow = getStyle(ele,attr) * 100; }else{ var iNow = parseInt(getStyle(ele,attr)); } let speed = (obj[attr] - iNow)/10; speed = speed < 0 ? Math.floor(speed) : Math.ceil(speed); // 只要有一个属性到目标,就停了,不对 // 必须所有属性到目标,才能停 // 只要有一个属性没到目标,绝对不能停 // 用状态来标记到底要不要停止计时器 // 只要有一个属性没到目标:绝对不能清除计时器 if(iNow !== obj[attr]){ i = false; } if(attr == "opacity"){ ele.style.opacity = (iNow + speed)/100; }else{ ele.style[attr] = iNow + speed + "px"; } } // 如果每次计时器执行结束,所有属性都执行了一遍之后,状态还是true,表示,没有被改成false,如果没有被改成false,表示没有属性没到终点,那么状态还是false就不清除 if(i){ clearInterval(ele.t); // 用户决定在动画结束时要执行的功能,万一用户没传参,做个默认判断 if(cb){ cb(); } // cb && cb(); } }, 30); } function getStyle(ele,attr){ if(ele.currentStyle){ return ele.currentStyle[attr]; }else{ return getComputedStyle(ele,false)[attr]; } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持hwidc。