JavaScript jQuery 实现banner(轮播图)

效果：

JSON数据：

[
  {
    "url": "https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=1133216305,48749125&fm=26&gp=0.jpg",
    "link": "https://www.jd.com",
    "title": "京东",
    "alt": "京东"
  },
  {
    "url": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1552566827&di=e764ec5f93592fbfee214fa17f6b4ae5&imgtype=jpg&er=1&src=http%3A%2F%2Fpic.90sjimg.com%2Fdesign%2F00%2F07%2F77%2F64%2F561221d452fe4.jpg",
    "link": "https://www.taobao.com",
    "title": "淘宝",
    "alt": "天猫"
  },
  {
    "url": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1551972170779&di=3d03a9d4aa48b12fdf937b3dd06c8fa2&imgtype=0&src=http%3A%2F%2Fimg.zcool.cn%2Fcommunity%2F01aa6d55d137156ac725baa0e6971c.jpg%401280w_1l_2o_100sh.png",
    "link": "https://www.tmall.com",
    "title": "天猫",
    "alt": "天猫"
  },
  {
    "url": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1552567034&di=50eac16f578786c7fe66ccc1e38a9acb&imgtype=jpg&er=1&src=http%3A%2F%2Fgss0.baidu.com%2F9fo3dSag_xI4khGko9WTAnF6hhy%2Fzhidao%2Fpic%2Fitem%2F1ad5ad6eddc451daebe2553fb4fd5266d11632c9.jpg",
    "link": "https://www.baidu.com",
    "title": "百度",
    "alt": "百度"
  },
  {
    "url": "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1551823210051&di=8c1c79ff108688568f9a9af8954a0bd0&imgtype=jpg&src=http%3A%2F%2Fimg3.imgtn.bdimg.com%2Fit%2Fu%3D660414558%2C1171548186%26fm%3D214%26gp%3D0.jpg",
    "link": "https://www.19lou.com/creampic-fid-58-t-9331399727863700-p-9741399727863972-nodigest-all-dateline.html",
    "title": "图片",
    "alt": "图片"
  }
]

实现：

html

    
    
    
    




    

        

        

    

    

        

        

    

    

        
Text
        
Text
    

    

        
    

    
    

css:

body {
    margin: 0;
    padding: 0;
}

#banner {
    position: relative;
    margin: 20px auto;
    overflow: hidden;
    height: 460px;
    width: 1200px;
    border-radius: 4px;
    background-color: white;
    cursor: pointer;
    background-color: gray;
}

#img-wrap img {
    object-fit: cover;
    -o-object-fit: cover;
    overflow: hidden;
    position: absolute;
}

#img-wrap {
    overflow: hidden;
    position: absolute;
    top: 60px;
    bottom: 0;
    padding: 0;
    margin: 0;
}


#btn-menu, #btn-menu li {
    list-style: none;
    float: left;
    margin: 0;
    padding: 0;
    border: none;
}

#btn-menu li {
    line-height: 60px;
    font-size: large;
    color: #eee;
    width: 400px;
    text-align: center;
}

#btn-menu .selected {
    color: #0ff;
}

#btn-menu li:hover {
    background-color: rgba(0, 255, 255, .2);
}


#btn-menu {
    width: 100%;
    top: 0;
    position: absolute;
    background-color: rgba(200, 200, 200, .4);
}

.btn {
    position: absolute;
    width: 40px;
    top: 220px;
    height: 80px;
    background: url(img/arrow.png) rgba(0, 0, 0, 0.05) center no-repeat;
    border-radius: 2px;
}

#next {
    right: 0;
}

#prev {
    transform: rotate(180deg);
    left: 0;
}

.btn:hover {
    background-color: rgba(255, 255, 255, .2);
}

#mask, #mask-help {
    position: absolute;
    height: 70px;
    text-align: center;
}

.mask-bg {
    background-color: #000;
    height: 60px;
    border-radius: 2px;
}

#mask-help {
    left: -100%;
}

.triangle {
    display: block;
    width: 0;
    height: 0;
    border-width: 10px 16px 0;
    border-style: solid;
    border-color: #555 transparent transparent;
    top: 60px;
    position: absolute;
    left: 50%;
    margin-left: -16px;
    z-index: 999;
}

javaScript:

var intervalId;
$.easing['sin'] = function (v) {
    return v * Math.sin(Math.PI / 2);
};
$.getJSON('data/banner.json', (bannerData) => {
    $('#prev').click(prev);
    $('#next').click(next);
    if (!bannerData || bannerData.length < 1) {
        return;
    }

    var speed;
    $('#banner').bind('mouseover mouseout', function (event) {
        clearInterval(intervalId);
        event.type === 'mouseout' && showAndNone();
    });
    const btnMenu = $('#btn-menu');
    btnMenu.html(bannerData.reduce((html, item) => html + '
' + item.title + '
', ''));
    const width = btnMenu.width() / bannerData.length;
    const btns = btnMenu.children('li').css({width: width}).click(function () {
        pics.idx = $(this).index();
        moveToIdx();
    });
    const imgWrap = $('#img-wrap').click(function () {
        window.open(bannerData[pics.idx].link, '_blank');
    }).css({left: 0, width: bannerData.length + '00%'});

    const imgWidth = imgWrap.width() / bannerData.length;


    imgWrap.html(bannerData.reduce((html, item) => html + '', ''));

    const pics = imgWrap.children('img').css({width: imgWidth}).each(function (i, e) {
        $(e).css({left: i * imgWidth})
    });
    pics.idx = pics.prevIdx = 0;
    const mask = $('#mask');
    const maskHelp = $('#mask-help');
    mask.css({left: 0, right: width * (pics.length - 1)});
    maskHelp.css({left: -width, right: imgWidth});
    btns.eq(0).addClass('selected');


    function setDefaultPicsLeft() {
        pics.each((i, e) => {
            $(e).css({left: i * imgWidth});
        });
    }


    function prepare() {
        maskHelp.stop(true).css({left: -width, right: imgWidth});
        mask.stop(true).css({left: width * pics.prevIdx, right: width * (pics.length - 1 - pics.prevIdx)});
        speed = Math.sqrt(Math.abs(pics.idx - pics.prevIdx)) * 300;
    }

    function next() {
        ++pics.idx;
        prepare();
        if (pics.idx > pics.length - 1) {
            pics.idx = 0;
            mask.animate(getAnimate(imgWidth, -width), speed);
            maskHelp.animate(getAnimate(0, imgWidth - width), speed);
        } else {
            maskAnimate();
        }
        moveToNextOrPrev(true);
    }


    function getAnimate(left, right) {
        return {
            left: [left, 'swing'],
            right: [right, 'sin']
        };
    }

    function maskAnimate() {
        mask.animate(getAnimate(width * pics.idx, width * (pics.length - 1 - pics.idx)), speed);
    }

    function moveToNextOrPrev(isNext) {
        imgWrap.stop(true, true).css({left: -imgWidth}).animate({left: isNext ? -2 * imgWidth : 0}, speed);
        pics.eq(pics.prevIdx).css({left: imgWidth}).siblings().css({left: -imgWidth});
        pics.eq(pics.idx).css({left: isNext ? 2 * imgWidth : 0});
        update();
    }

    function prev() {
        --pics.idx;
        prepare();
        if (pics.idx < 0) {
            pics.idx = pics.length - 1;
            mask.animate(getAnimate(0, imgWidth), speed);
            maskHelp.css({left: imgWidth, right: -width}).animate(getAnimate(imgWidth - width, 0), speed);
        } else {
            maskAnimate();
        }
        moveToNextOrPrev(false);
    }

    function moveToIdx() {
        prepare();
        setDefaultPicsLeft();
        maskAnimate();
        imgWrap.stop(true).css({left: -pics.prevIdx * imgWidth}).animate({left: -imgWidth * pics.idx}, speed);
        update();
    }

    function update() {
        btns.eq(pics.prevIdx).removeClass('selected');
        btns.eq(pics.idx).addClass('selected');
        pics.prevIdx = pics.idx;
    }

    function showAndNone() {
        intervalId = setInterval(next, 3000);
    }


    showAndNone();
});