javascript实现焦点图轮播效果代码示例

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<meta><title>JS实现焦点图轮播效果</title><style>
* {
margin: 0;
padding: 0;
text-decoration: none;
}

body {
padding: 20px;
}

#container {
width: 600px;
height: 400px;
border: 3px solid #333;
overflow: hidden;
position: relative;
}

#list {
width: 4200px;
height: 400px;
position: absolute;
z-index: 1;
}

#list img {
float: left;
}

#buttons {
position: absolute;
height: 10px;
width: 100px;
z-index: 2;
bottom: 20px;
left: 250px;
}

#buttons span {
cursor: pointer;
float: left;
border: 1px solid #fff;
width: 10px;
height: 10px;
border-radius: 50%;
background: #333;
margin-right: 5px;
}

#buttons .on {
background: orangered;
}

.arrow {
cursor: pointer;
display: none;
line-height: 39px;
text-align: center;
font-size: 36px;
font-weight: bold;
width: 40px;
height: 40px;
position: absolute;
z-index: 2;
top: 180px;
background-color: RGBA(0, 0, 0, .3);
color: #fff;
}

.arrow:hover {
background-color: RGBA(0, 0, 0, .7);
}

#container:hover .arrow {
display: block;
}

#prev {
left: 20px;
}

#next {
right: 20px;
}
</style><script>
window.onload = function() {
var container = document.getElementById(&#39;container&#39;);
var list = document.getElementById(&#39;list&#39;);
var buttons = document.getElementById(&#39;buttons&#39;).getElementsByTagName(&#39;span&#39;);
var prev = document.getElementById(&#39;prev&#39;);
var next = document.getElementById(&#39;next&#39;);
var index = 1;
var len = 5;
var animated = false;
var interval = 3000;
var timer;

function animate(offset) {
    if(offset == 0) {
        return;
    }
    animated = true;
    var time = 300;
    var inteval = 10;
    var speed = offset / (time / inteval);
    var left = parseInt(list.style.left) + offset;

    var go = function() {
        if((speed > 0 && parseInt(list.style.left) < left) ||
         (speed < 0 && parseInt(list.style.left) > left)) {
            list.style.left = parseInt(list.style.left) + speed + &#39;px&#39;;
            setTimeout(go, inteval);
        } else {
            list.style.left = left + &#39;px&#39;;
            if(left > -200) {
                list.style.left = -600 * len + &#39;px&#39;;
            }
            if(left < (-600 * len)) {
                list.style.left = &#39;-600px&#39;;
            }
            animated = false;
        }
    }
    go();
}

function showButton() {
    for(var i = 0; i < buttons.length; i++) {
        if(buttons[i].className == &#39;on&#39;) {
            buttons[i].className = &#39;&#39;;
            break;
        }
    }
    buttons[index - 1].className = &#39;on&#39;;
}

function play() {
    timer = setTimeout(function() {
        next.onclick();
        play();
    }, interval);
}

function stop() {
    clearTimeout(timer);
}

next.onclick = function() {
    if(animated) {
        return;
    }
    if(index == 5) {
        index = 1;
    } else {
        index += 1;
    }
    animate(-600);
    showButton();
}
prev.onclick = function() {
    if(animated) {
        return;
    }
    if(index == 1) {
        index = 5;
    } else {
        index -= 1;
    }
    animate(600);
    showButton();
}

for(var i = 0; i < buttons.length; i++) {
    buttons[i].onclick = function() {
        if(animated) {
            return;
        }
        if(this.className == &#39;on&#39;) {
            return;
        }
        var myIndex = parseInt(this.getAttribute(&#39;index&#39;));
        var offset = -600 * (myIndex - index);

        animate(offset);
        index = myIndex;
        showButton();
    }
}

container.onmouseover = stop;
container.onmouseout = play;

play();

}
</script><div>
<div>

<!-- 放最后的一张图片 -图片需要改为自己的图片路径 -->
<img  alt="javascript实现焦点图轮播效果代码示例" ><img  alt="javascript实现焦点图轮播效果代码示例" ><img  alt="javascript实现焦点图轮播效果代码示例" ><img  alt="javascript实现焦点图轮播效果代码示例" ><img  alt="javascript实现焦点图轮播效果代码示例" ><img  alt="javascript实现焦点图轮播效果代码示例" ><!-- 放第一张的图片 --><img  alt="javascript实现焦点图轮播效果代码示例" >
</div>
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