前端學習-第二階段-day06

阿新 • • 發佈：2020-12-29

練習目標

輪播圖,滑鼠移入輪播停止，移出繼續輪播，點選小圓點自動跳轉相應圖片
在這裡插入圖片描述

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title 
>
    <style>
        * {
            padding: 0;
            margin: 0;
            list-style: none;
        }

        .box {
            width: 600px;
            height: 400px;
            margin: 50px auto;
            border: 2px solid teal;
            position: relative;
            overflow 
: hidden;
        }

        .box ul {
            width: 2400px;
            position: absolute;
            left: 0px;
        }

        .box li {
            float: left;
        }

        .box p {
            position: absolute;
            bottom: 10px;
            width: 100%;
            text-align 
: center;
        }

        .box p span {
            display: inline-block;
            width: 15px;
            height: 15px;
            background: #000;
            border-radius: 50%;
            margin-right: 5px;
        }

        .box p .active {
            background: teal;
        }
    </style>
</head>

<body>
    <div class="box">
       
        <ul>
            <li><img src="./image/t1.png" alt=""></li>
            <li><img src="./image/t2.png" alt=""></li>
            <li><img src="./image/t3.png" alt=""></li>
            <li><img src="./image/t4.png" alt=""></li>
        </ul>
        <p><span class='active'></span><span></span><span></span><span></span></p>
    </div>

    <script src="./js/myPackage.js"></script>
    <script>
        var oSpan = document.getElementsByTagName("span");
        var oBox = document.getElementsByTagName("div")[0];
        var oUl = oBox.getElementsByTagName("ul")[0];
        var n = 0;
        var over = setInterval(auto, 1000);

        function auto() {
            n++;
            if (-600 * n == -2400) {
                n = -1;
            }
            running(oUl, "left", 30, -600 * n);
            for (i = 0; i < oSpan.length; i++) {
                oSpan[i].className = "";
            }
            oSpan[n].className = "active";
        }
        oUl.onmouseover = function () {
            clearInterval(over);
           
        }
        oUl.onmouseout = function () {
            clearInterval(over);
            
            over = setInterval(auto, 1000);
            
        }
        
        for (b = 0; b < oSpan.length; b++) {
            oSpan[b].index = b;
            oSpan[b].onclick = function () {
                
                clearInterval(over);
                oUl.style.left = (this.index) * (-600) + "px";
                for (i = 0; i < oSpan.length; i++) {
                    oSpan[i].className = "";
                }
                this.className = "active";
               
                over = setInterval(auto, 1000);
            }

        }
    </script>
</body>

</html>

js程式碼

/* 
*作用：獲取元素的樣式
*@parm {object} elem：標籤
*@parm {string} attr：屬性
*/
function getStyle(elem,arr){//標籤：elem  屬性：attribute
    if(window.getComputedStyle){
        //標準
        var value= getComputedStyle(elem)[arr];
    }else{
        //IE
        var value=elem.currentStyle[arr];
    }
    return value
}

/* 
*作用：運動元素
*@parm {object} elem：標籤
*@parm {string} attr：屬性
*@parm {number} step：步長
*@parm {number} target：目標值
*/
function running(elem, attr, step, target) { //運動元素elem,屬性attr,步長step,目標值target
    step = parseInt(getStyle(elem, attr)) < target ? step : -step;
    clearInterval(elem.out);
    elem.out = setInterval(function () {
        
        var n = parseInt(getStyle(elem, attr)) + step;
        if ((n <= target && step) < 0||(n >= target && step > 0)) {
            n = target;
            clearInterval(elem.out);
        }
        elem.style.left = n + "px";

    }, 30);
}
``