原生js实现fadein 和 fadeout

         js里面设置DOM节点透明度的函数属性:filter= "alpha(opacity=" + value+ ")"(兼容ie)和opacity=value/100(兼容FF和GG)。

         先来看看设置透明度的兼容性代码:

function setOpacity(ele, opacity) {

    if (ele.style.opacity != undefined) {

        ///兼容FF和GG和新版本IE

        ele.style.opacity = opacity / 100;



    } else {

        ///兼容老版本ie

        ele.style.filter = "alpha(opacity=" + opacity + ")";

    }

}

关于有的小伙伴这样写:

function setOpacity(ele, opacity) {

    if (document.all) {

        ///兼容ie

        ele.style.filter = "alpha(opacity=" + opacity + ")";

    }

    ele {

        ///兼容FF和GG

        ele.style.opacity = opacity / 100;

    }

}

我想说这样在IE10下运行有问题,点了之后没反应。因为IE10支持opacity属性不支持filter了,这个方法不可取。

 

fadein   函数代码:

function fadein(ele, opacity, speed) {

    if (ele) {

        var v = ele.style.filter.replace("alpha(opacity=", "").replace(")", "") || ele.style.opacity;

        v < 1 && (v = v * 100);

        var count = speed / 1000;

        var avg = count < 2 ? (opacity / count) : (opacity / count - 1);

        var timer = null;

        timer = setInterval(function() {

            if (v < opacity) {

                v += avg;

                setOpacity(ele, v);

            } else {

                clearInterval(timer);

            }

        }, 500);

    }

}

 

fadeout   函数代码:

function fadeout(ele, opacity, speed) {

    if (ele) {

        var v = ele.style.filter.replace("alpha(opacity=", "").replace(")", "") || ele.style.opacity || 100;

        v < 1 && (v = v * 100);

        var count = speed / 1000;

        var avg = (100 - opacity) / count;

        var timer = null;

        timer = setInterval(function() {

            if (v - avg > opacity) {

                v -= avg;

                setOpacity(ele, v);

            } else {

                clearInterval(timer);

            }

        }, 500);

    }

}

 

 

下面给一个demo示例:

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

    <title></title>

<script type="text/javascript" src="fade.js"></script>

    <script type="text/javascript">

         

        window.onload = function () {





            document.getElementById('Button1').onclick = function () {



                fadeout(document.getElementById('DV'), 0, 6000);



            }

            document.getElementById('Button2').onclick = function () {



                fadein(document.getElementById('DV'), 80, 6000);



            }

        }

    </script>

</head>

<body>



    <div id="DV" style="background-color: green; width: 400px; height: 400px;"></div>

    <input id="Button1" type="button" value="button" />

    <input id="Button2" type="button" value="button" />



</body>

</html>

有什么更好的实现方式可以留言。。。

 

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